NMP rectification device

Abstract

The utility model relates to an NMP (N-Methyl Pyrrolidone) rectification device which is used for distilling NMP waste liquid and comprises a distillation tower, a collecting tank, a vacuum pump and a condensation assembly, a supporting table is arranged on the outer side of the collecting tank, the condensation assembly and the distillation tower are arranged on the supporting table, the vacuum pump is communicated with the collecting tank through a pipeline I, a communicating pipe is arranged between the distillation tower and the collecting tank, and the communicating pipe is communicated with the collecting tank through a pipeline II. The condensation assembly is used for enabling steam passing through the communicating pipe to be subjected to heat exchange and converted into liquid, and then the liquid flows into the collecting tank. According to the NMP rectification device, after the vacuum pump is started, the distillation tower can be vacuumized so as to reduce the boiling point of the NMP waste liquid and reduce the energy consumption for heating the NMP waste liquid, and air does not exist in a vacuum environment, so that the NMP cannot be oxidized and discolored, the quality of the NMP is ensured, and the distilled NMP can return to the distillation tower to be distilled again.

Description

Technical Field

[0001] The utility model relates to the technical field of NMP waste liquid recovery, in particular to an NMP distillation device. Background Art

[0002] NMP stands for N-methylpyrrolidone, which is a commonly used organic solvent. It is widely used in the refining of advanced lubricants, the synthesis of polymers, insulating materials, pesticides, pigments, cleaning agents, etc. It is also widely used in the motor industry, such as polyvinylidene fluoride (PVDF), motor auxiliary materials for lithium-ion batteries, photolithography degumming and liquid removal, and LCD liquid crystal material production.

[0003] During the NMP process, NMP will gradually be contaminated by impurities and become waste liquid, which not only causes resource loss but also has adverse effects on the environment. Therefore, it is necessary to recycle the waste liquid of NMP. Since the boiling point of NMP is 202°C, NMP needs to be heated to a higher temperature in the initial heating to evaporate it. Since more energy is consumed when evaporating the same volume of NMP, there is a disadvantage of high energy consumption. In addition, NMP will be partially oxidized when it contacts with oxides in the air, causing it to change color. Therefore, an NMP distillation device is proposed. Utility Model Content

[0004] Based on the above description, the utility model provides an NMP distillation device, which solves the technical problem of high energy consumption of the existing NMP distillation device.

[0005] The utility model solves the above technical problems with the following technical solutions: an NMP distillation device for distilling NMP waste liquid, comprising a distillation tower, a collecting tank, a vacuum pump and a condensation assembly, wherein a support platform is arranged on the outside of the collecting tank, the condensation assembly and the distillation tower are arranged on the support platform, the vacuum pump is connected to the collecting tank through a pipeline 1, a connecting pipe is arranged between the distillation tower and the collecting tank, and the condensation assembly is used to allow the steam passing through the connecting pipe to be heat exchanged and converted into liquid, and the liquid then flows into the collecting tank;

[0006] When the vacuum pump is working, the distillation tower can be evacuated to reduce the boiling point of the NMP waste liquid.

[0007] On the basis of the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, the condensation component includes a liquid pump component, a condenser, a cooling water tank and a reflux pipe, wherein the reflux pipe is arranged between the outlet end of the condenser and the cooling water tank, the condenser is arranged on the outside of the connecting pipe, and is used to allow the steam passing through the connecting pipe to be heat exchanged and converted into liquid, and the liquid pump component is used to allow the water in the cooling water tank to circulate through the condenser.

[0009] Furthermore, the condenser is arranged at an angle to facilitate water reflux.

[0010] Furthermore, the liquid pump component includes a liquid pump, a liquid pumping pipe and a liquid outlet pipe, wherein the liquid pumping pipe connects the cooling water tank with the inlet end of the liquid pump, and the liquid outlet pipe connects the outlet end of the liquid pump with the inlet end of the condenser.

[0011] Furthermore, a cooling air port is provided on the cooling water tank.

[0012] Furthermore, a spray rack is provided in the distillation tower, a joint 1 is provided on the outside of the liquid outlet pipe, and a receiving pipe is provided between the joint 1 and the spray rack to allow water in the cooling water tank to flow out from the spray rack, and an electromagnetic valve 1 is provided on the outside of the receiving pipe and the liquid outlet pipe.

[0013] Furthermore, a joint 2 is provided on the outside of the liquid extraction pipe, a branch pipe is provided on the outside of the joint 2, one end of the branch pipe away from the joint 2 is located in the collecting tank, and solenoid valve 2 is provided on the outside of the branch pipe and the liquid extraction pipe, so that the liquid collected in the collecting tank can return to the distillation tower.

[0014] Furthermore, an electric heating jacket is provided on the outer side of the collecting tank.

[0015] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0016] The NMP distillation device allows the distillation tower to be evacuated after the vacuum pump is started, so as to lower the boiling point of the NMP waste liquid and reduce the energy consumption for heating the NMP waste liquid. In the vacuum environment, air does not exist, so the NMP will not be oxidized and discolored. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of an NMP distillation device provided in an embodiment of the utility model;

[0018] Figure 2 for Figure 1 A structural diagram from another perspective;

[0019] Figure 3 for Figure 2 Schematic diagram of the structure when cut away;

[0020] Figure 4 It is a structural schematic diagram of a condensing component and its connection structure in an embodiment of the utility model.

[0021] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0022] 1. Distillation tower; 2. Collecting tank; 3. Vacuum pump; 4. Condensation assembly; 41. Condenser; 42. Cooling water tank; 43. Reflux pipe; 44. Liquid extraction pump; 45. Liquid extraction pipe; 46. Liquid outlet pipe; 47. Cooling air outlet; 5. Support platform; 6. Pipeline 1; 7. Connecting pipe; 8. Spray rack; 9. Connector 1; 10. Receiver pipe; 11. Solenoid valve 1; 12. Connector 2; 13. Branch pipe; 14. Solenoid valve 2; 15. Electric heating jacket. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0024] like Figure 1 As shown, an NMP distillation device in this embodiment is used for distilling NMP waste liquid, including a distillation tower 1, a collecting tank 2, a vacuum pump 3, a condensation assembly 4, a support platform 5, a pipeline 6 and a connecting pipe 7, wherein the support platform 5 is fixed to the outside of the collecting tank 2 by bolts, and is used to support the condensation assembly 4, the distillation tower 1 and the vacuum pump 3, so that the overall structure is relatively compact, the pipeline 6 is assembled and arranged at the vacuum exhaust port of the vacuum pump 3, so that the vacuum pump 3 can be connected with the collecting tank 2 through the pipeline 6, the connecting pipe 7 is inclined and detachably connected between the distillation tower 1 and the collecting tank 2, and the two ends of the connecting pipe 7 are respectively located at the top of the distillation tower 1 and the collecting tank 2, and the condensation assembly 4 is used to allow the steam passing through the connecting pipe 7 to be heat exchanged and converted into liquid, and the liquid then flows into the collecting tank 2.

[0025] Since the distillation tower 1 is connected to the collecting tank 2 through the connecting pipe 7, after the vacuum pump 3 is started, the distillation tower 1 can be evacuated to reduce the boiling point of the NMP waste liquid. In the vacuum environment, air does not exist, so NMP will not be oxidized and discolored.

[0026] To facilitate understanding of the above condensation assembly 4, a specific description is given here. Figure 2 As shown, the condensation assembly 4 includes a liquid pump component, a condenser 41, a cooling water tank 42 and a return pipe 43, wherein the return pipe 43 is fixed by bolts between the outlet end of the condenser 41 and the cooling water tank 42, and the condenser 41 is detachably arranged on the outside of the connecting pipe 7 to allow the steam passing through the connecting pipe 7 to be heat exchanged and converted into liquid, and the liquid pump component is used to allow the water in the cooling water tank 42 to circulate through the condenser 41.

[0027] Specifically, Figure 2-4 As shown, the liquid pump component includes a liquid pump 44, a liquid suction pipe 45 and a liquid outlet pipe 46, wherein the liquid suction pipe 45 connects the cooling water tank 42 with the inlet end of the liquid pump 44, and the liquid outlet pipe 46 connects the outlet end of the liquid pump 44 with the inlet end of the condenser 41.

[0028] It should be noted that a closable liquid inlet is fixedly provided on the left side of the distillation tower 1 for initially allowing NMP waste liquid to be injected into the distillation tower 1 , and the liquid inlet needs to be closed during operation.

[0029] Thus, the whole working process is to inject the pre-heated NMP waste liquid from the liquid inlet of the distillation tower 1, start the vacuum pump 3, and when the distillation tower 1 is evacuated, there is no air in the vacuum environment, so that NMP will not be oxidized and discolored, and in the vacuum environment, due to the pressure reduction, the boiling point of the NMP waste liquid is reduced, and the pre-heated NMP solution can be evaporated. In this process, the liquid pump 44 is started at the same time, and a circulation pipeline is formed through the liquid pumping pipe 45, the liquid outlet pipe 46, the condenser 41, the reflux pipe 43 and the cooling water tank 42, so that the steam passing through the connecting pipe 7 can be heat exchanged and converted into liquid, and the liquid is the distilled NMP solution, and the NMP solution will then flow into the collection tank 2 and be collected by the collection tank 2.

[0030] In the above working process, since there is no need to heat the NMP waste liquid to 202° C., energy consumption is reduced and oxidation discoloration of NMP is avoided.

[0031] Furthermore, as a preferred solution for the condenser 41, the condenser 41 is tilted to facilitate water reflux.

[0032] It should be noted that if Figure 4 As shown, water will exchange heat and rise in temperature during the circulation of the cooling water tank 42. In order to lower the water temperature, a cooling air outlet 47 is fixedly provided on the cooling water tank 42. The cooling air outlet 47 is used for natural ventilation. Of course, it is understandable that the cooling air outlet 47 can be connected to a mechanical ventilation fan or cooling fins can be provided on the cooling water tank 42. The fan and the cooling fins are not shown, and are used to improve the cooling efficiency.

[0033] Considering that after the distillation is completed, some impurities will remain at the bottom of the distillation tower 1. In order to remove the impurities, such as Figure 2 and 4 As shown, in a certain embodiment, a spray rack 8 is fixed by bolts in the distillation tower 1, a joint 9 is threadedly connected to the outer side of the liquid outlet pipe 46, and a receiving pipe 10 is detachably provided between the joint 9 and the spray rack 8, so that the water in the cooling water tank 42 can flow out from the spray rack 8, and a solenoid valve 11 is detachably provided on the outer side of the receiving pipe 10 and the liquid outlet pipe 46.

[0034] It should be noted that the solenoid valve 11 outside the liquid outlet pipe 46 is located above the connector 9, so that it does not affect the normal conduction of the connector 9, and a discharge pipe is fixedly provided at the bottom of the distillation tower 1.

[0035] At this time, the working process of the water in the cooling water tank 42 flowing out from the spray rack 8 is to close the solenoid valve 11 on the outside of the liquid outlet pipe 46, open the solenoid valve 11 on the outside of the receiving pipe 10, start the liquid pump 44, and conduct through the liquid pumping pipe 45, the liquid outlet pipe 46, the joint 9 and the receiving pipe 10, so that the water in the cooling water tank 42 can flow out from the spray rack 8, and then clean the impurities at the bottom of the distillation tower 1 and discharge them from the outlet pipe.

[0036] Considering that the distilled NMP may not be pure enough, in order to return the NMP to the distillation column 1 for redistillation, further, as Figure 2 and 4 As shown, in a certain embodiment, a joint 2 12 is threadedly connected to the outer side of the liquid extraction tube 45, and a branch pipe 13 is detachably provided on the outer side of the joint 2 12. The end of the branch pipe 13 away from the joint 2 12 is located in the collecting tank 2, and a solenoid valve 2 14 is detachably provided on the outer sides of the branch pipe 13 and the liquid extraction tube 45, so that the liquid collected in the collecting tank 2 can be returned to the distillation tower 1.

[0037] It should be noted that an electric heating jacket 15 is fixedly provided on the outer side of the collecting tank 2. The electric heating jacket 15 is a prior art and will not be described in detail here. It should be noted that it is mainly used here to heat the NMP distillation solution entering the collecting tank (2) so that it can be redistilled later, and the solenoid valve 14 on the outer side of the liquid extraction pipe 45 is located above the connector 12.

[0038] In this way, the electric heating jacket 15 is started to heat the NMP solution in the collecting tank 2, the electromagnetic valve 2 14 on the outside of the extraction pipe 45 and the electromagnetic valve 1 11 on the outside of the liquid outlet pipe 46 are closed, the electromagnetic valve 2 14 on the outside of the branch pipe 13 and the electromagnetic valve 1 11 on the outside of the receiving pipe 10 are opened, and the extraction pump 44 is started to allow the NMP solution in the collecting tank 2 to return to the distillation tower 1, and finally the vacuum pump 3 is restarted to allow the distillation tower 1 to be evacuated again and distillation can be restarted.

[0039] The above are only preferred specific implementation methods of the utility model, but the protection scope of the utility model is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the utility model, who makes equivalent replacements or changes based on the technical scheme and utility model concept of the utility model, should be covered by the protection scope of the utility model.

Claims

1. A NMP distillation device for distilling NMP waste liquid, It is characterized in that The invention comprises a distillation tower (1), a collecting tank (2), a vacuum pump (3) and a condensation assembly (4), wherein a support platform (5) is arranged outside the collecting tank (2), the condensation assembly (4) and the distillation tower (1) are both arranged on the support platform (5), the vacuum pump (3) is connected to the collecting tank (2) through a pipeline (6), a connecting pipe (7) is arranged between the distillation tower (1) and the collecting tank (2), and the condensation assembly (4) is used to allow the steam passing through the connecting pipe (7) to be heat-exchanged and converted into liquid, and the liquid then flows into the collecting tank (2); When the vacuum pump (3) is working, the distillation tower (1) can be evacuated to reduce the boiling point of the NMP waste liquid.

2. A NMP distillation device according to claim 1, Features: The condensation assembly (4) comprises a liquid pump component, a condenser (41), a cooling water tank (42) and a return pipe (43), wherein the return pipe (43) is arranged between the outlet end of the condenser (41) and the cooling water tank (42), the condenser (41) is arranged on the outside of the connecting pipe (7) to allow the steam passing through the connecting pipe (7) to be heat-exchanged and converted into liquid, and the liquid pump component is used to allow the water in the cooling water tank (42) to circulate through the condenser (41).

3. A NMP distillation device according to claim 2, Features: The condenser (41) is arranged at an angle to facilitate water reflux.

4. A NMP distillation device according to claim 2, Features: The liquid pump component comprises a liquid suction pump (44), a liquid suction pipe (45) and a liquid outlet pipe (46), wherein the liquid suction pipe (45) connects the cooling water tank (42) with the inlet end of the liquid suction pump (44), and the liquid outlet pipe (46) connects the outlet end of the liquid suction pump (44) with the inlet end of the condenser (41).

5. A NMP distillation device according to claim 2, Features: The cooling water tank (42) is provided with a cooling air port (47).

6. A NMP distillation device according to claim 4, Features: The distillation tower (1) is provided with a spray rack (8), a joint (9) is provided on the outside of the liquid outlet pipe (46), a receiving pipe (10) is provided between the joint (9) and the spray rack (8), so that water in the cooling water tank (42) can flow out from the spray rack (8), and a solenoid valve (11) is provided on the outside of the receiving pipe (10) and the liquid outlet pipe (46).

7. A NMP distillation device according to claim 6, Features: A second joint (12) is provided on the outside of the liquid extraction pipe (45), and a branch pipe (13) is provided on the outside of the second joint (12). One end of the branch pipe (13) away from the second joint (12) is located in the collection tank (2), and a second solenoid valve (14) is provided on the outside of the branch pipe (13) and the liquid extraction pipe (45), so that the liquid collected in the collection tank (2) can be returned to the distillation tower (1).

8. A NMP distillation device according to claim 7, Features: An electric heating jacket (15) is provided on the outer side of the collecting tank (2).

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