Rectifying tower waste heat recovery system in DMSO recovery process

Abstract

The utility model discloses a rectifying tower waste heat recovery system in a DMSO (Dimethylsulfoxide) recovery process, which comprises a second-effect rectifying tower and a first-effect rectifying tower, and a solution containing low-concentration DMSO is rectified by the second-effect rectifying tower and then flows into the first-effect rectifying tower through a pipeline to be further rectified; the system further comprises a second-effect rectifying tower heat exchanger, a steam compressor and a second-effect rectifying tower reboiler, a DMSO solution firstly passes through the second-effect rectifying tower heat exchanger and then flows into the tower bottom of the second-effect rectifying tower, and the second-effect rectifying tower is connected with the hot side of the second-effect rectifying tower heat exchanger through a pipeline; the tower top of the first-effect rectifying tower is connected with a steam compressor through a pipeline, the steam compressor compresses steam and then is connected with the hot side of a second-effect rectifying tower reboiler, and the second-effect rectifying tower reboiler further heats the second-effect rectifying tower through a circulating pipeline. According to the utility model, heat of residual high-temperature steam in the first-effect rectifying tower and the second-effect rectifying tower can be efficiently recycled, meanwhile, the steam is recycled through steam circulation, and the outsourcing amount of the steam is reduced.

Description

Technical Field

[0001] The utility model relates to a rectification column waste heat recovery system in the DMSO recovery process, belonging to the technical field of rectification column waste heat recovery. Background Technique

[0002] Many production processes often involve the separation of miscible liquid mixtures, such as petroleum refining, purification of organic synthesis products, solvent recovery, and compliance treatment before waste liquid discharge. There are various separation methods, and the most commonly used in industry is rectification.

[0003] Dimethyl sulfoxide (DMSO) is a sulfur-containing organic compound, which is a colorless transparent liquid at room temperature and is a hygroscopic flammable liquid. It has the characteristics of high polarity, high boiling point, good thermal stability, aprotic, and miscible with water, and can dissolve in most organic substances such as ethanol, propanol, benzene, and chloroform, and is known as the "universal solvent".

[0004] Currently, when the existing rectification column recovers DMSO, a large amount of waste heat still remains unused in the separated gas phase and liquid phase, resulting in a large loss of medium-pressure steam. At the same time, if you want to improve the distillation efficiency and increase the bottom temperature of the column, more steam will be consumed.

[0005] To sum up, it is obvious that there are inconveniences and defects in the actual use of the existing technology, so it is necessary to improve it. Content of the Utility Model

[0006] Aiming at the deficiencies in the background technique, the utility model provides a rectification column waste heat recovery system in the DMSO recovery process, which can efficiently recover and utilize the heat of the remaining high-temperature steam in the first-effect rectification column and the second-effect rectification column. At the same time, through steam circulation, the steam can be reused again, and the external purchase amount of steam can be reduced.

[0007] To solve the above technical problems, the utility model adopts the following technical solutions:

[0008] A rectification column waste heat recovery system in the DMSO recovery process includes a second-effect rectification column and a first-effect rectification column. The solution containing low-concentration DMSO is first rectified by the second-effect rectification column and then flows into the first-effect rectification column through a pipeline for further rectification;

[0009] It also includes a second-effect rectification column heat exchanger, a steam compressor, and a second-effect rectification column reboiler. The DMSO solution first passes through the second-effect rectification column heat exchanger and then flows into the bottom of the second-effect rectification column. The second-effect rectification column is connected to the hot side of the second-effect rectification column heat exchanger through a pipeline;

[0010] The top of the first-effect rectification column is connected to the steam compressor through a pipeline. The steam compressor compresses the steam and connects it to the hot side of the second-effect rectification column reboiler. The second-effect rectification column reboiler further heats the second-effect rectification column through a circulation pipeline.

[0011] Further, it also includes a reboiler for the first-effect rectification column. The reboiler for the first-effect rectification column is connected to the first-effect rectification column through a circulation pipeline, and the reboiler for the first-effect rectification column provides heat energy for the first-effect rectification column.

[0012] Further, a part of the steam flowing out of the reboiler for the first-effect rectification column flows into a steam generator, and the steam generator is used to provide medium-pressure steam for the reboiler for the first-effect rectification column.

[0013] Further, another part of the steam flowing out of the reboiler for the first-effect rectification column flows into a condensate heat exchanger, and the external cold water absorbs the waste heat of the steam after passing through the condensate heat exchanger and becomes hot water.

[0014] Further, a flash tank is provided between the first-effect rectification column and the second-effect rectification column. The liquid in the first-effect rectification column flows from the bottom of the column into the flash tank, and the flash tank flows into the first-effect rectification column through a pipeline.

[0015] Further, a feed pipeline preheating heat exchanger is provided on the pipe section between the second-effect rectification column heat exchanger and the second-effect rectification column. Desalted hot water flows through the feed pipeline preheating heat exchanger to further heat the solution.

[0016] Further, the cold side of the second-effect rectification column heat exchanger is connected to the second-effect rectification column condensate tank; the cold side of the second-effect rectification column reboiler is connected to the first-effect rectification column condensate tank.

[0017] After the present utility model adopts the above technical solutions, compared with the prior art, it has the following advantages:

[0018] 1. The remaining high-temperature steam in the second-effect rectification column flows from the top of the column into the second-effect rectification column heat exchanger to preheat the solution in the input pipeline, and the heat of the high-temperature steam in the second-effect rectification column is recovered; the remaining high-temperature steam in the first-effect rectification column flows into the reboiler for the second-effect rectification column after being pressurized by a steam compressor and serves as the heat source for the second-effect rectification column, so that the remaining high-temperature steam in the first-effect rectification column is efficiently recovered and utilized.

[0019] 2. A part of the steam flowing out of the reboiler for the first-effect rectification column flows into the steam generator, and transporting steam into the steam generator can reduce the amount of purchased steam; another part flows into the condensate heat exchanger, and the external cold water absorbs the waste heat of the steam after passing through the condensate heat exchanger and becomes hot water, recovering the heat energy.

[0020] The present utility model will be described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the present utility model.

[0022] In the figure,

[0023] 1-two-effect distillation tower, 2-two-effect distillation tower heat exchanger, 3-feed pipeline preheating heat exchanger, 4-single-effect distillation tower, 5-single-effect distillation tower reboiler, 6-steam compressor, 7-two-effect distillation tower reboiler, 8-condensate heat exchanger, 9-steam generator, 10-two-effect distillation tower condenser, 11-single-effect distillation tower condenser, 12-flash evaporator. DETAILED DESCRIPTION

[0024] In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific implementation methods of the utility model are now described with reference to the accompanying drawings.

[0025] like Figure 1 As shown, the utility model provides a distillation tower waste heat recovery system in the DMSO recovery process, comprising a second-effect distillation tower 1 and a first-effect distillation tower 4, a solution containing low-concentration DMSO is first distilled in the second-effect distillation tower 1 and then flows into the first-effect distillation tower 4 through a pipeline for further distillation;

[0026] The system also includes a second-effect distillation tower heat exchanger 2, a steam compressor 6 and a second-effect distillation tower reboiler 7. The DMSO solution first passes through the second-effect distillation tower heat exchanger 2 and then flows into the bottom of the second-effect distillation tower 1. The second-effect distillation tower 1 is connected to the hot side of the second-effect distillation tower heat exchanger 2 through a pipeline, and the cold side of the second-effect distillation tower heat exchanger 2 is connected to the second-effect distillation tower condenser 10;

[0027] The top of the first-effect distillation tower 4 is connected to the steam compressor 6 through a pipeline. The steam compressor 6 compresses the steam and is connected to the hot side of the reboiler 7 of the second-effect distillation tower. As the heat source of the reboiler 7 of the second-effect distillation tower, the reboiler 7 of the second-effect distillation tower further heats the second-effect distillation tower 1 through a circulation pipeline. The cold side of the reboiler 7 of the second-effect distillation tower is connected to the condenser 11 of the first-effect distillation tower.

[0028] The system further comprises a first-effect distillation tower reboiler 5 , which is connected to the first-effect distillation tower 4 through a circulation pipeline, and the first-effect distillation tower reboiler 5 provides heat energy for the first-effect distillation tower 4 .

[0029] A portion of the steam flowing out of the first-effect distillation tower reboiler 5 flows into the steam generator 9, and the steam generator 9 is used to provide medium-pressure steam to the first-effect distillation tower reboiler 5. Transporting steam into the steam generator 9 can reduce the amount of purchased steam.

[0030] Another part of the steam flowing out of the reboiler 5 of the first-effect distillation tower flows into the condensate heat exchanger 8. After passing through the condensate heat exchanger 8, the external cold water absorbs the residual heat of the steam and becomes hot water, thereby recovering the heat energy.

[0031] A flash evaporator 12 is provided between the first-effect distillation tower 4 and the second-effect distillation tower 1. The liquid in the first-effect distillation tower 4 flows into the flash evaporator 12 from the bottom of the tower. The flash evaporator 12 flows into the first-effect distillation tower 4 through a pipeline. The flash evaporator 12 vaporizes the solution to minimize the solids (polymers or salts) present in the material fed to the distillation section.

[0032] A feed pipeline preheating heat exchanger 3 is provided on the pipe section between the second-effect distillation tower heat exchanger 2 and the second-effect distillation tower 1. Desalinated hot water flows in the feed pipeline preheating heat exchanger 3 to further heat the solution.

[0033] The specific working principle of the utility model:

[0034] The remaining high-temperature steam in the second-effect distillation tower 1 flows from the top of the tower into the second-effect distillation tower heat exchanger 2 to preheat the solution in the input pipeline and recover the heat of the high-temperature steam in the second-effect distillation tower 1; the remaining high-temperature steam in the first-effect distillation tower 4 is pressurized by the steam compressor 6 and flows into the second-effect distillation tower reboiler 7 as the heat source of the second-effect distillation tower 1, so that the remaining high-temperature steam in the first-effect distillation tower 4 can be efficiently recovered and utilized.

[0035] Part of the steam flowing out of the reboiler 5 of the first-effect distillation tower flows into the steam generator 9. Transporting steam into the steam generator 9 can reduce the amount of purchased steam; the other part flows into the condensate heat exchanger 8. After passing through the condensate heat exchanger 8, the external cold water absorbs the residual heat of the steam and becomes hot water, thereby recovering the heat energy.

[0036] The above is an example of the best implementation of the utility model, and the parts not described in detail are common knowledge of ordinary technicians in this field. The protection scope of the utility model is based on the content of the claims, and any equivalent transformation based on the technical inspiration of the utility model is also within the protection scope of the utility model.

Claims

1. A distillation tower waste heat recovery system in a DMSO recovery process, characterized in that: The method comprises a second-effect distillation tower (1) and a first-effect distillation tower (4), wherein a solution containing low-concentration DMSO is first distilled in the second-effect distillation tower (1) and then flows into the first-effect distillation tower (4) through a pipeline for further distillation; The second-effect distillation tower also includes a second-effect distillation tower heat exchanger (2), a steam compressor (6) and a second-effect distillation tower reboiler (7). The DMSO solution first passes through the second-effect distillation tower heat exchanger (2) and then flows into the bottom of the second-effect distillation tower (1). The second-effect distillation tower (1) is connected to the hot side of the second-effect distillation tower heat exchanger (2) through a pipeline. The top of the first-effect distillation tower (4) is connected to a steam compressor (6) through a pipeline. The steam compressor (6) compresses the steam and is connected to the hot side of a reboiler (7) of a second-effect distillation tower. The reboiler (7) of the second-effect distillation tower further heats the second-effect distillation tower (1) through a circulation pipeline.

2. The distillation tower waste heat recovery system in a DMSO recovery process as claimed in claim 1, characterized in that: The invention also comprises a first-effect distillation tower reboiler (5), which is connected to the first-effect distillation tower (4) through a circulation pipeline, and the first-effect distillation tower reboiler (5) provides heat energy for the first-effect distillation tower (4).

3. A distillation tower waste heat recovery system in a DMSO recovery process as claimed in claim 2, characterized in that: A portion of the steam flowing out of the reboiler (5) of the first-effect distillation tower flows into the steam generator (9), and the steam generator (9) is used to provide medium-pressure steam to the reboiler (5) of the first-effect distillation tower.

4. The distillation tower waste heat recovery system in a DMSO recovery process as claimed in claim 3, characterized in that: Another part of the steam flowing out of the reboiler (5) of the first-effect distillation tower flows into the condensate heat exchanger (8), and the external cold water absorbs the residual heat of the steam after passing through the condensate heat exchanger (8) to become hot water.

5. The distillation tower waste heat recovery system in a DMSO recovery process according to claim 1, characterized in that: A flash evaporator (12) is provided between the first-effect distillation tower (4) and the second-effect distillation tower (1). Liquid in the first-effect distillation tower (4) flows into the flash evaporator (12) from the bottom of the tower, and the flash evaporator (12) flows into the first-effect distillation tower (4) through a pipeline.

6. The distillation tower waste heat recovery system in a DMSO recovery process according to claim 1, characterized in that: A feed pipeline preheating heat exchanger (3) is provided on the pipe section between the second-effect distillation tower heat exchanger (2) and the second-effect distillation tower (1). Desalinated hot water flows in the feed pipeline preheating heat exchanger (3) to further heat the solution.

7. The distillation tower waste heat recovery system in a DMSO recovery process according to claim 1, characterized in that: The cold side of the second-effect distillation tower heat exchanger (2) is connected to the second-effect distillation tower condenser (10); the cold side of the second-effect distillation tower reboiler (7) is connected to the first-effect distillation tower condenser (11).

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