DMF (Dimethyl Formamide) waste liquid purification treatment device

Abstract

The utility model discloses a DMF (Dimethyl Formamide) waste liquid purification treatment device which comprises a first rectification unit, a second rectification unit, a third rectification unit and an adsorption unit, the first rectification unit, the second rectification unit and the third rectification unit are sequentially connected in series, the first rectification unit comprises a first rectification tower, a first tower top liquid tank and a first reboiler; the second rectification unit comprises a second rectification tower, a second tower top liquid tank and a second reboiler; the third rectification unit comprises a third rectification tower, a third tower top liquid tank and a third reboiler; the second rectifying tower is connected with a first reboiler, and the first reboiler is connected with a second tower top liquid tank; the third rectifying tower is connected with a second reboiler, the second reboiler is connected with a third tower top liquid tank, and the second tower top liquid tank and the third tower top liquid tank are both connected with the adsorption unit.

Description

Technical Field

[0001] The utility model belongs to the technical field of DMF waste liquid treatment, and particularly relates to a DMF waste liquid purification treatment device. Background Art

[0002] The coated textile industry generates a large amount of organic wastewater containing DMF during its production process. This wastewater contains DMF at a concentration of 10%-25%, requiring concentration and purification through thermal processes such as distillation. The purified DMF can then be recycled. However, the wastewater can contain 0.05%-0.5% DMF, and direct discharge of this wastewater into water bodies can cause serious environmental pollution. If biochemical treatment is used, DMF's biological toxicity can easily lead to microbial poisoning, resulting in unstable wastewater treatment processes. This necessitates the use of chemical pretreatment processes, but this treatment method is costly and cannot recycle the low concentration of DMF in the wastewater, resulting in a waste of resources. Utility Model Content

[0003] In view of this, in order to overcome the defects of the prior art, the purpose of the present invention is to provide a DMF waste liquid purification treatment device, which can directly reduce the DMF content in the effluent to 0-0.01%, improve the process operation stability, and effectively reduce the treatment cost.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A DMF waste liquid purification treatment device comprises a first distillation unit, a second distillation unit, a third distillation unit and an adsorption unit, wherein the first distillation unit, the second distillation unit and the third distillation unit are connected in series in sequence, the first distillation unit comprises a first distillation tower, a first tower top liquid tank and a first reboiler, the second distillation unit comprises a second distillation tower, a second tower top liquid tank and a second reboiler, and the third distillation unit comprises a third distillation tower, a third tower top liquid tank and a third reboiler; the second distillation tower is connected to the first reboiler, and the first reboiler is connected to the second tower top liquid tank; the third distillation tower is connected to the second reboiler, and the second reboiler is connected to the third tower top liquid tank, and the second tower top liquid tank and the third tower top liquid tank are both connected to the adsorption unit; the first distillation tower, the second distillation tower and the third distillation tower are all negative pressure distillation towers.

[0006] According to some preferred implementation aspects of the present invention, the first distillation unit also includes a cooler, the first distillation tower includes a first distillation tower top outlet and a first distillation tower bottom outlet, the cooler includes a cooler tube side inlet and a cooler tube side outlet, the first tower top liquid tank includes a first tower top liquid tank inlet, the first distillation tower top outlet is connected to the cooler tube side inlet, and the cooler tube side outlet is connected to the first tower top liquid tank inlet.

[0007] According to some preferred embodiments of the present invention, the first distillation tower further includes a first outlet, a first inlet and a second inlet, the first reboiler includes a first reboiler tube side inlet, a first reboiler tube side outlet, a first reboiler shell side inlet and a first reboiler shell side outlet, the bottom outlet of the first distillation tower is connected to the first reboiler tube side inlet, and the first reboiler tube side outlet is connected to the second inlet.

[0008] According to some preferred implementation aspects of the present invention, the second distillation tower includes a second distillation tower top outlet and a second distillation tower bottom outlet, the second tower top liquid tank includes a second tower top liquid tank inlet, the second distillation tower top outlet is connected to the first reboiler shell side inlet, and the first reboiler shell side outlet is connected to the second tower top liquid tank inlet.

[0009] According to some preferred implementation aspects of the present invention, the second distillation tower further includes a second outlet, a third inlet and a fourth inlet, the second reboiler includes a second reboiler tube side inlet, a second reboiler tube side outlet, a second reboiler shell side inlet and a second reboiler shell side outlet, the first outlet of the first distillation tower is connected to the third inlet of the second distillation tower, the bottom outlet of the second distillation tower is connected to the second reboiler tube side inlet, and the second reboiler tube side outlet is connected to the fourth inlet.

[0010] According to some preferred implementation aspects of the present invention, the third distillation tower includes a third distillation tower top outlet and a third distillation tower bottom outlet, the third tower top liquid tank includes a third tower top liquid tank inlet, the third distillation tower top outlet is connected to the second reboiler shell side inlet, and the second reboiler shell side outlet is connected to the third tower top liquid tank inlet.

[0011] According to some preferred implementation aspects of the present invention, the third distillation tower also includes a fifth inlet and a sixth inlet, the third reboiler includes a third reboiler tube side inlet, a third reboiler tube side outlet, a third reboiler shell side inlet and a third reboiler shell side outlet, the second outlet of the second distillation tower is connected to the fifth inlet of the third distillation tower, the bottom outlet of the third distillation tower is connected to the third reboiler tube side inlet, and the third reboiler tube side outlet is connected to the sixth inlet.

[0012] According to some preferred implementation aspects of the present invention, it also includes a waste liquid preheater and a steam supply unit, the waste liquid preheater includes a waste liquid preheater shell side inlet and a waste liquid preheater tube side outlet, the steam supply unit is connected to the shell side inlet of the third reboiler, and the shell side outlet of the third reboiler is connected to the shell side inlet of the waste liquid preheater.

[0013] According to some preferred implementation aspects of the present invention, the waste liquid preheater is used to preheat the DMF waste liquid, and the waste liquid preheater pipe outlet is connected to the first inlet of the first distillation tower.

[0014] According to some preferred implementation aspects of the present invention, the adsorption unit includes a plurality of adsorption tanks connected in parallel and / or in series, and the adsorption medium of the adsorption tanks is activated carbon.

[0015] Compared with the prior art, the benefits of the present invention are as follows: a DMF waste liquid purification treatment device of the present invention, by using a negative pressure first distillation tower, a second distillation tower and a third distillation tower combined with an adsorption unit, can, on the one hand, realize efficient recovery of DMF in DMF waste liquid; on the other hand, the DMF content in the effluent of the medium and high concentration DMF waste liquid after passing through the three distillation towers in sequence is directly reduced to 0-0.01%, and can directly enter the biochemical system for treatment, which greatly reduces the operating difficulty of the biochemical process treatment caused by the high DMF content in the effluent of the existing treatment device, reduces the treatment cost, and simultaneously reduces the concentration of COD and total nitrogen in the effluent, reduces the back-end treatment process load, improves the process operation stability, and achieves the dual purposes of recycling and cost reduction and efficiency improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a structural schematic diagram of a DMF waste liquid purification treatment device in a preferred embodiment of the present utility model;

[0018] Wherein, the accompanying drawings are marked as follows:

[0019] First distillation unit-1, first distillation tower-11, first distillation tower top outlet-111, first distillation tower bottom outlet-112, first outlet-113, first inlet-114, second inlet-115, first overhead liquid tank-12, first overhead liquid tank inlet-121, first overhead liquid tank outlet-122, first reboiler-13, first reboiler tube-side inlet-131, first reboiler tube-side outlet-132, first reboiler shell-side inlet-133, first reboiler shell-side outlet-134, cooler-14, cooler tube-side inlet-141, cooler tube-side outlet-142;

[0020] Second distillation unit-2, second distillation tower-21, second distillation tower top outlet-211, second distillation tower bottom outlet-212, second outlet-213, third inlet-214, fourth inlet-215, second overhead liquid tank-22, second overhead liquid tank inlet-221, second overhead liquid tank outlet-222, second reboiler-23, second reboiler tube-side inlet-231, second reboiler tube-side outlet-232, second reboiler shell-side inlet-233, second reboiler shell-side outlet-234;

[0021] Third distillation unit 3, third distillation tower 31, third distillation tower top outlet 311, third distillation tower bottom outlet 312, third outlet 313, fifth inlet 314, sixth inlet 315, third overhead liquid tank 32, third overhead liquid tank inlet 321, third overhead liquid tank outlet 322, third reboiler 33, third reboiler tube-side inlet 331, third reboiler tube-side outlet 332, third reboiler shell-side inlet 333, third reboiler shell-side outlet 334;

[0022] Adsorption unit 4, adsorption tank 41, adsorption inlet 411, adsorption outlet 412, steam inlet 413, desorption outlet 414;

[0023] Waste liquid preheater-5, waste liquid preheater shell side inlet-51, waste liquid preheater tube side inlet-52, waste liquid preheater tube side outlet-53. DETAILED DESCRIPTION

[0024] In order to help those skilled in the art better understand the technical solutions of the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0025] Reference Figure 1 The DMF waste liquid purification treatment device in this embodiment is used to treat DMF waste liquid, and includes a first distillation unit 1, a second distillation unit 2, a third distillation unit 3, an adsorption unit 4, a steam supply unit and a waste liquid preheater 5. The first distillation unit 1, the second distillation unit 2 and the third distillation unit 3 are connected in series in sequence; wherein, the waste liquid preheater 5 includes a waste liquid preheater shell side inlet 51, a waste liquid preheater tube side inlet 52 and a waste liquid preheater tube side outlet 53, and the DMF waste liquid enters the waste liquid preheater 5 from the waste liquid preheater tube side inlet 52 for preheating.

[0026] The first distillation unit 1 includes a first distillation tower 11, a first overhead liquid tank 12, a first reboiler 13, and a cooler 14. The first distillation tower 11 is a negative pressure distillation tower, and includes a first distillation tower top outlet 111, a first distillation tower bottom outlet 112, a first outlet 113, a first inlet 114, and a second inlet 115. The cooler 14 includes a cooler tube side inlet 141 and a cooler tube side outlet 142. The first overhead liquid tank 12 includes a first overhead liquid tank inlet 121 and a first overhead liquid tank outlet 122. The first reboiler 13 includes a first reboiler tube side inlet 131, a first reboiler tube side outlet 132, a first reboiler shell side inlet 133, and a first reboiler shell side outlet 134. Specifically, the waste liquid preheater tube side outlet 53 is connected to the first inlet 114 of the first distillation tower 11, the top outlet 111 of the first distillation tower is connected to the cooler tube side inlet 141, the cooler tube side outlet 142 is connected to the first top liquid tank inlet 121, the bottom outlet 112 of the first distillation tower is connected to the first reboiler tube side inlet 131, and the first reboiler tube side outlet 132 is connected to the second inlet 115.

[0027] The DMF waste liquid after preheating in the waste liquid preheater 5 enters the first distillation tower 11 and is carried out rectifying. The overhead vapor in the first distillation tower 11 enters the cooler 14 by the cooler tube side inlet 141 and is condensed after flowing out by the cooler tube side outlet 142 and enters the first overhead liquid tank 12 by the first overhead liquid tank inlet 121 and is temporarily stored. After the first distillation tower overhead liquid in the first overhead liquid tank 12 is full, it is directly discharged to the sewage pool by the first overhead liquid tank outlet 122. Because the residual DMF concentration in the overhead water of the first distillation tower 11 is lower (less than 0.005%), and contains more other volatile organic compounds, such as alcohols, ethers, etc., the wastewater has good biodegradability and can be discharged into the wastewater collecting tank and is processed biochemically. The bottom liquid of the first distillation tower 11 is recycled back to the first distillation tower 11 and is processed rectifying again after the first reboiler 13 heats.

[0028] The second distillation unit 2 includes a second distillation tower 21, a second overhead liquid tank 22 and a second reboiler 23. The second distillation tower 21 is a negative pressure distillation tower. The second distillation tower 21 includes a second distillation tower top outlet 211, a second distillation tower bottom outlet 212, a second outlet 213, a third inlet 214 and a fourth inlet 215; the second overhead liquid tank 22 includes a second overhead liquid tank inlet 221 and a second overhead liquid tank outlet 222; the second reboiler 23 includes a second reboiler tube side inlet 231, a second reboiler tube side outlet 232, a second reboiler shell side inlet 233 and a second reboiler shell side outlet 234. The first outlet 113 of the first distillation tower 11 is connected to the third inlet 214 of the second distillation tower 21, the top outlet 211 of the second distillation tower is connected to the first reboiler shell side inlet 133, and the first reboiler shell side outlet 134 is connected to the second top liquid tank inlet 221; the bottom outlet 212 of the second distillation tower is connected to the second reboiler tube side inlet 231, and the second reboiler tube side outlet 232 is connected to the fourth inlet 215.

[0029] The concentrated liquid after distillation in the first distillation tower 11 flows from its first outlet 113 through the third inlet 214 of the second distillation tower 21 to enter the second distillation tower 21 for further distillation. The overhead vapor in the second distillation tower 21 flows from the second distillation tower overhead outlet 211 through the first reboiler shell-side inlet 133 to enter the first reboiler 13, where it exchanges heat with the bottom liquid of the first distillation tower 11 in the first reboiler 13. The concentrated liquid then flows from the first reboiler shell-side outlet 134 through the second overhead liquid tank inlet 221 to enter the second overhead liquid tank 22 for storage. Similarly, the bottom liquid of the second distillation tower 21 is heated in the second reboiler 23 and then circulated back to the second distillation tower 21 for further distillation.

[0030] The third distillation unit 3 includes a third distillation tower 31, a third overhead liquid tank 32 and a third reboiler 33. The third distillation tower 31 is a negative pressure distillation tower. The third distillation tower 31 includes a third distillation tower top outlet 311, a third distillation tower bottom outlet 312, a third outlet 313, a fifth inlet 314 and a sixth inlet 315; the third overhead liquid tank 32 includes a third overhead liquid tank inlet 321 and a third overhead liquid tank outlet 322; the third reboiler 33 includes a third reboiler tube side inlet 331, a third reboiler tube side outlet 332, a third reboiler shell side inlet 333 and a third reboiler shell side outlet 334. The second outlet 213 of the second distillation tower 21 is connected to the fifth inlet 314 of the third distillation tower 31, the top outlet 311 of the third distillation tower is connected to the second reboiler shell side inlet 233, and the second reboiler shell side outlet 234 is connected to the third top liquid tank inlet 321; the bottom outlet 312 of the third distillation tower is connected to the third reboiler tube side inlet 331, and the third reboiler tube side outlet 332 is connected to the sixth inlet 315; the steam supply unit is connected to the third reboiler shell side inlet 333, and the third reboiler shell side outlet 334 is connected to the waste liquid preheater shell side inlet 51.

[0031] The concentrated liquid after distillation in the second distillation tower 21 enters the third distillation tower 31 through the second outlet 213 thereof via the fifth inlet 314 of the third distillation tower 31 for further distillation. The overhead vapor in the third distillation tower 31 enters the second reboiler 23 through the second reboiler shell-side inlet 233 from the third distillation tower top outlet 311 to exchange heat with the bottom liquid of the second distillation tower 21 in the second reboiler 23. The liquid then enters the third overhead liquid tank 32 through the second reboiler shell-side outlet 234 to be stored. Similarly, the bottom liquid of the third distillation tower 31 is heated in the third reboiler 33 and then recycled back to the third distillation tower 31 for further distillation. The concentrated liquid (finished DMF) obtained after distillation in the third distillation tower 31 is directly discharged and collected from the third outlet 313 of the third distillation tower 31.

[0032] Since the residual DMF concentration in the top water of the second distillation tower 21 and the third distillation tower 31 is relatively high (DMF content 0.05%-0.3%), it is collected separately in the second top liquid tank 22 and the third top liquid tank 32, and then flows to the adsorption unit 4 for adsorption treatment.

[0033] The adsorption unit 4 includes multiple adsorption tanks 41 connected in parallel and / or in series. In this embodiment, two adsorption tanks 41 are provided, and switching between the series and parallel connections of the two adsorption tanks 41 is achieved by switching valves. Each adsorption tank 41 includes an adsorption inlet 411, an adsorption outlet 412, a steam inlet 413, and a desorption outlet 414. The second tower top liquid tank outlet 222 and the third tower top liquid tank outlet 322 are both connected to the adsorption inlet 411, allowing the adsorption tank 41 to be adsorbed for treatment. After adsorption treatment, the DMF concentration in the wastewater is reduced to less than 0.01%, and the wastewater can be directly discharged through the adsorption outlet 412 into the sewage tank for biochemical treatment. In addition, the adsorption medium of the adsorption tank 41 is activated carbon, which can be coal, wood or coconut shell activated carbon. By regularly subjecting the adsorption medium to high-temperature steam activation and regeneration, the hot regeneration steam enters the adsorption tank 41 that has been saturated with adsorption from the steam inlet 413 of the adsorption tank 41, and the DMF adsorbed by the activated carbon in the adsorption tank 41 can be desorbed at high temperature and condensed to form a high-concentration DMF waste liquid. The DMF content in the waste liquid is about 5%-10%. The high-concentration DMF waste liquid enters the waste liquid storage tank through the desorption outlet 414 for storage, and then is concentrated for distillation recovery; the performance of the activated carbon after regeneration is restored and can also be recycled.

[0034] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A DMF waste liquid purification treatment device, characterized in that, It includes a first distillation unit, a second distillation unit, a third distillation unit and an adsorption unit, wherein the first distillation unit, the second distillation unit and the third distillation unit are connected in series in sequence, the first distillation unit includes a first distillation tower, a first overhead liquid tank and a first reboiler, the second distillation unit includes a second distillation tower, a second overhead liquid tank and a second reboiler, and the third distillation unit includes a third distillation tower, a third overhead liquid tank and a third reboiler; the second distillation tower is connected to the first reboiler, and the first reboiler is connected to the second overhead liquid tank; the third distillation tower is connected to the second reboiler, and the second reboiler is connected to the third overhead liquid tank, and the second overhead liquid tank and the third overhead liquid tank are both connected to the adsorption unit; the first distillation tower, the second distillation tower and the third distillation tower are all negative pressure distillation towers.

2. DMF waste liquid purification treatment unit according to claim 1, is characterized in that, The first distillation unit also includes a cooler, the first distillation tower includes a first distillation tower top outlet and a first distillation tower bottom outlet, the cooler includes a cooler tube side inlet and a cooler tube side outlet, the first tower top liquid tank includes a first tower top liquid tank inlet, the first distillation tower top outlet is connected to the cooler tube side inlet, and the cooler tube side outlet is connected to the first tower top liquid tank inlet.

3. DMF waste liquid purification treatment unit according to claim 2, is characterized in that, The first distillation tower also includes a first outlet, a first inlet and a second inlet. The first reboiler includes a first reboiler tube side inlet, a first reboiler tube side outlet, a first reboiler shell side inlet and a first reboiler shell side outlet. The bottom outlet of the first distillation tower is connected to the first reboiler tube side inlet, and the first reboiler tube side outlet is connected to the second inlet.

4. DMF waste liquid purification treatment unit according to claim 3, is characterized in that, The second distillation tower includes a second distillation tower top outlet and a second distillation tower bottom outlet, the second tower top liquid tank includes a second tower top liquid tank inlet, the second distillation tower top outlet is connected to the first reboiler shell side inlet, and the first reboiler shell side outlet is connected to the second tower top liquid tank inlet.

5. DMF waste liquid purification treatment unit according to claim 4, is characterized in that, The second distillation tower also includes a second outlet, a third inlet and a fourth inlet, the second reboiler includes a second reboiler tube side inlet, a second reboiler tube side outlet, a second reboiler shell side inlet and a second reboiler shell side outlet, the first outlet of the first distillation tower is connected to the third inlet of the second distillation tower, the bottom outlet of the second distillation tower is connected to the second reboiler tube side inlet, and the second reboiler tube side outlet is connected to the fourth inlet.

6. DMF waste liquid purification treatment unit according to claim 5, is characterized in that, The third distillation tower includes a third distillation tower top outlet and a third distillation tower bottom outlet, the third tower top liquid tank includes a third tower top liquid tank inlet, the third distillation tower top outlet is connected to the second reboiler shell side inlet, and the second reboiler shell side outlet is connected to the third tower top liquid tank inlet.

7. DMF waste liquid purification treatment unit according to claim 6, is characterized in that, The third distillation tower also includes a fifth inlet and a sixth inlet, the third reboiler includes a third reboiler tube side inlet, a third reboiler tube side outlet, a third reboiler shell side inlet and a third reboiler shell side outlet, the second outlet of the second distillation tower is connected to the fifth inlet of the third distillation tower, the bottom outlet of the third distillation tower is connected to the third reboiler tube side inlet, and the third reboiler tube side outlet is connected to the sixth inlet.

8. DMF waste liquid purification treatment unit according to claim 7, is characterized in that, It also includes a waste liquid preheater and a steam supply unit, the waste liquid preheater includes a waste liquid preheater shell side inlet and a waste liquid preheater tube side outlet, the steam supply unit is connected to the shell side inlet of the third reboiler, and the shell side outlet of the third reboiler is connected to the shell side inlet of the waste liquid preheater.

9. DMF waste liquid purification treatment unit according to claim 8, is characterized in that, The waste liquid preheater is used to preheat the DMF waste liquid, and the waste liquid preheater pipe outlet is connected to the first inlet of the first distillation tower.

10. DMF waste liquid purification treatment unit according to claim 1, is characterized in that, The adsorption unit includes a plurality of adsorption tanks connected in parallel and / or in series, and the adsorption medium of the adsorption tanks is activated carbon.

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