Cooling water recycling system in hexamethylenediamine production process

Abstract

The utility model relates to a cooling water recycling system in a hexamethylenediamine production process, which comprises a pipeline system, a control valve adjusting system, a first cooling water circulating pump, a second cooling water circulating pump, a first cooling water heat exchanger and a second cooling water heat exchanger, cooling water generated in the hexamethylenediamine production process is subjected to heat exchange and temperature adjustment through the control valve adjusting system and the pipeline system and then enters the system again to be recycled. The device is ingenious in design, ensures the stability of the temperature, flow and pressure of cooling water, ensures the stability and reliability of a cooling water source and ensures the continuous cyclic utilization of the cooling water by preferably modifying the cooling water circulating pump and the cooling water heat exchanger, and can reduce the use amount of the cooling water in the production process of hexamethylenediamine for the current situation, thereby reducing the production cost. The effects of saving resources and reducing energy consumption are achieved, and good economic benefits and development space are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical cooling water recovery and reuse, in particular to a cooling water recovery and reuse system in the production process of hexamethylenediamine. Background Technique

[0002] Hexamethylenediamine is an important organic compound, mainly used in organic synthesis, epoxy curing agents, chemical reagents, etc., and is one of the main raw materials for the production of nylon 66, with a melting point of 42 - 45°C. In the production process of hexamethylenediamine, a large amount of low-pressure steam (SL) or 60°C desalted water (WH60) is required to provide heat tracing for the hexamethylenediamine material pipeline. In addition, a large amount of 45°C desalted water (WH45) is required in the refining process to cool the overhead distillate of each distillation column by heat exchange, which will generate a large amount of 45°C desalted water return (WH45R) and 60°C desalted water return (WH60R). If not recycled, it will cause a large waste of water resources and energy. Through investigation and research, it is found that the temperature difference between the 45°C desalted water return and the 60°C desalted water is not significant, and the temperature difference between the 60°C desalted water return and the 45°C desalted water is also not much. How to scientifically and reasonably utilize the recovered water and recycle it again is a bottleneck problem.

[0003] How to design a system with ingenious design, through the optimized transformation of the cooling water heat exchanger and the circulation pump, to ensure the stability of the temperature, flow rate and pressure of the cooling water, realize the recycling of the cooling water, and ensure the continuous and stable production of the device is the technical problem to be solved at present. Content of the Utility Model

[0004] In order to solve the problem that a large amount of cooling water cannot be recycled in the existing hexamethylenediamine production, and reduce the consumption of water resources and energy, the utility model provides a cooling water recovery and reuse system in the production process of hexamethylenediamine. Through the optimized transformation of the cooling water heat exchanger and the circulation pump, the stability of the temperature, flow rate and pressure of the cooling water is ensured, the recycling of the cooling water is realized, and the purpose of continuous and stable production of the device can be ensured.

[0005] The technical solution adopted by the utility model to solve the above technical problems is: a cooling water recovery and reuse system in the production process of hexamethylenediamine, including a pipeline system, a control valve adjustment system, a first cooling water circulation pump, a second cooling water circulation pump, a first cooling water heat exchanger and a second cooling water heat exchanger.

[0006] As a further optimization solution for the cooling water recycling system in the above-mentioned adipic diamine production process, the pipeline system includes a 60°C desalted water supply pipeline, a 60°C desalted water return pipeline, a low-pressure steam pipeline, a 45°C desalted water return pipeline, a steam condensate pipeline, a 45°C desalted water supply pipeline, a 45°C desalted water circulation pipeline, a cooling water circulation pump inlet pipeline, a circulating water supply pipeline, a circulating water return pipeline, and a desalted water make-up pipeline.

[0007] As a further optimization solution for the cooling water recycling system in the above-mentioned adipic diamine production process, the control valve regulating system includes a 60°C desalted water temperature control regulating valve, a 45°C desalted water pressure control regulating valve, and a 45°C desalted water temperature control regulating valve.

[0008] As a further optimization solution for the cooling water recycling system in the above-mentioned adipic diamine production process, the 45°C desalted water return pipeline is connected to the first cooling water heat exchanger. The 45°C desalted water return water in the 45°C desalted water return pipeline is heated and raised in temperature by the low-pressure steam pipeline in the first cooling water heat exchanger, and then connected to the 60°C desalted water supply pipeline for recycling in the 60°C desalted water supply system. The temperature of the first cooling water heat exchanger is controlled by the 60°C desalted water temperature control regulating valve. The steam condensate generated after heat exchange in the low-pressure steam pipeline is sent into the steam condensate pipe network through the steam condensate pipeline.

[0009] As a further optimization solution for the cooling water recycling system in the above-mentioned adipic diamine production process, the 60°C desalted water return pipeline is connected to the second cooling water heat exchanger. The 60°C desalted water return water in the 60°C desalted water return pipeline is cooled by heat exchange with the circulating water supply pipeline in the second cooling water heat exchanger, and then connected to the cooling water circulation pump inlet pipeline for recycling in the 45°C desalted water supply system. The temperature of the second cooling water heat exchanger is controlled by the 45°C desalted water temperature control regulating valve.

[0010] As a further optimization solution for the cooling water recycling system in the above-mentioned adipic diamine production process, the desalted water make-up pipeline is arranged on the cooling water circulation pump inlet pipeline at the outlet end of the second cooling water heat exchanger to supplement the insufficient flow in the cooling water circulation pump inlet pipeline.

[0011] As a further optimization solution for the cooling water recycling system in the above-mentioned adipic diamine production process, the first cooling water circulation pump and the second cooling water circulation pump are arranged in parallel, with one in normal use and the other in standby. The usage status of the first cooling water circulation pump and the second cooling water circulation pump can be switched at any time to ensure the continuous and stable operation of the system.

[0012] Compared with the prior art, the beneficial effects of the present utility model are:

[0013] The utility model includes a pipeline system, a control valve regulation system, a first cooling water circulation pump, a second cooling water circulation pump, a first cooling water heat exchanger and a second cooling water heat exchanger. The control valve regulation system and the pipeline system recycle the cooling water generated in the production process of hexamethylenediamine after heat exchange and temperature regulation and re-enter the system for recycling. Through the preferred transformation of the cooling water heat exchanger and the circulation pump, the utility model ensures the stability of the temperature, flow rate and pressure of the cooling water, realizes the recycling of the cooling water, and can ensure the continuous and stable production of the device. Brief Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of the technological process of the utility model;

[0015] Markings in the figure: 1. 60°C desalted water supply pipeline, 2. Low-pressure steam pipeline, 3. 45°C desalted water return pipeline, 4. Steam condensate pipeline, 5. 45°C desalted water supply pipeline, 6. 45°C desalted water circulation pipeline, 7. Cooling water circulation pump inlet pipeline, 8. Desalted water make-up pipeline, 9. 45°C desalted water return branch pipeline, 10. 60°C desalted water return pipeline, 11. Circulating water supply pipeline, 12. Circulating water return pipeline, 13. First cooling water circulation pump, 14. Second cooling water circulation pump, 15. First cooling water heat exchanger, 16. Second cooling water heat exchanger, 17. 60°C desalted water temperature control regulating valve, 18. 45°C desalted water pressure control regulating valve, 19. 45°C desalted water temperature control regulating valve. Detailed Description of the Preferred Embodiments

[0016] The following further describes in detail the specific embodiments of the utility model with reference to the accompanying drawings.

[0017] As Figure 1 shown, a cooling water recovery and reuse system in the production process of hexamethylenediamine includes a pipeline system, a control valve regulation system, a first cooling water circulation pump 13, a second cooling water circulation pump 14, a first cooling water heat exchanger 15 and a second cooling water heat exchanger 16. The control valve regulation system and the pipeline system recycle the cooling water generated in the production process of hexamethylenediamine after heat exchange and temperature regulation and re-enter the system for recycling.

[0018] The pipeline system includes a 60°C desalted water supply pipeline 1, a 60°C desalted water return pipeline 10, a low-pressure steam pipeline 2, a 45°C desalted water return pipeline 3, a steam condensate pipeline 4, a 45°C desalted water supply pipeline 5, a 45°C desalted water circulation pipeline 6, a cooling water circulation pump inlet pipeline 7, a circulating water supply pipeline 11, a circulating water return pipeline 12 and a desalted water make-up pipeline 8.

[0019] The described control valve regulating system includes a 60°C desalted water temperature control regulating valve 17, a 45°C desalted water pressure control regulating valve 18, and a 45°C desalted water temperature control regulating valve 19.

[0020] The 45°C desalted water return pipeline 3 is connected to the first cooling water heat exchanger 15. The 45°C desalted water return water in the 45°C desalted water return pipeline 3 is heated and raised in temperature by the low-pressure steam pipeline 2 in the first cooling water heat exchanger 15, and then connected to the 60°C desalted water supply pipeline 1 for recycling in the 60°C desalted water supply system. The temperature of the first cooling water heat exchanger 15 is controlled by the 60°C desalted water temperature control regulating valve 17. The steam condensate generated after heat exchange in the low-pressure steam pipeline 2 is sent into the steam condensate pipe network through the steam condensate pipeline 4.

[0021] The 60°C desalted water return pipeline 10 is connected to the second cooling water heat exchanger 16. The 60°C desalted water return water in the 60°C desalted water return pipeline 10 is cooled and reduced in temperature by heat exchange with the circulating water supply pipeline 11 in the second cooling water heat exchanger 16, and then connected to the cooling water circulation pump inlet pipeline 7 for recycling in the 45°C desalted water supply system. The temperature of the second cooling water heat exchanger 16 is controlled by the 45°C desalted water temperature control regulating valve 19.

[0022] The desalted water make-up pipeline 8 is arranged on the cooling water circulation pump inlet pipeline 7 at the outlet end of the second cooling water heat exchanger 16 to supplement the insufficient flow in the cooling water circulation pump inlet pipeline 7.

[0023] The first cooling water circulation pump 13 and the second cooling water circulation pump 14 are arranged in parallel, with one in normal use and the other in standby. The usage status of the first cooling water circulation pump 13 and the second cooling water circulation pump 14 can be switched at any time to ensure the continuous and stable operation of the system.

[0024] The working process of the recycling and reuse of cooling water in the present utility model is as follows:

[0025] Step 1: Generation of 60°C desalted water. As shown in the attached drawing, in a system for recycling and reuse of cooling water during the production of hexamethylenediamine, during the production process of the hexamethylenediamine plant, the 45°C desalted water return cooling water generated is heated by the first cooling water heat exchanger (15) and used as 60°C desalted water to provide pipeline tracing heat for the material jacket pipeline. The control state of the 60°C desalted water temperature control regulating valve (17) is set to "AUTO", and the set value is "60 °C". When the temperature of the 60°C desalted water is insufficient, the 60°C desalted water temperature control regulating valve (17) automatically opens, and low-pressure steam enters the cooling water heat exchanger (15) to exchange heat with the 45°C desalted water return cooling water. The generated steam condensate enters the steam condensate system pipe network through the steam trap. When the temperature of the 60°C desalted water reaches the target value, the opening of the 60°C desalted water temperature control regulating valve tends to be stable or closes.

[0026] Step 2: Generation of 45°C demineralized water. As shown in the attached drawings, in the cooling water recovery and reuse system during the production process of hexamethylenediamine, during the production process of the hexamethylenediamine unit, the 60°C demineralized water return water for cooling is cooled by the second cooling water heat exchanger (16) and then used as 45°C demineralized water to cool the distillate materials at the top of each distillation column through heat exchange. The control state of the 45°C demineralized water temperature control regulating valve (19) is set to "AUTO", and the set value is "45 °C". When the temperature of the 45°C demineralized water does not meet the requirements, the 45°C demineralized water temperature control regulating valve (19) automatically adjusts the opening degree and automatically adjusts the flow rate of the circulating water return cooling water to adjust the temperature of the 45°C demineralized water to the target value, and the opening degree of the 45°C demineralized water temperature control regulating valve (19) then tends to be stable.

[0027] Step 3: Regulation of the pressure of 45°C demineralized water. As shown in the attached drawings, the control state of the 45°C demineralized water pressure control regulating valve (18) is set to "AUTO", and the set value is "0.5 MPa". When the pressure of the 45°C demineralized water is low, the 45°C demineralized water return water pressure control regulating valve (18) automatically adjusts the opening degree, and the 45°C demineralized water return cooling water and the 60°C demineralized water return cooling water enter the second cooling water heat exchanger (16) to adjust the pressure of the 45°C demineralized water to the target value, and the opening degree of the 45°C demineralized water pressure control regulating valve (18) then tends to be stable or closed.

[0028] Step 4: Make-up of 45°C demineralized water. As shown in the attached drawings, in the cooling water recovery and reuse system during the production process of hexamethylenediamine, the demineralized water make-up pipeline (8) is connected to the inlet pipeline (7) of the cooling water circulation pump. When the flow rate of the 45°C demineralized water is insufficient, the corresponding valve on the demineralized water make-up pipeline can be opened to supplement demineralized water into the system as cooling water to ensure the stable operation of the hexamethylenediamine production unit.

[0029] The utility model is ingeniously designed. Through the preferred transformation of the cooling water circulation pump and the cooling water heat exchanger, the stability of the cooling water temperature, flow rate and pressure is ensured, the stability and reliability of the cooling water source are ensured, the continuous circulation and reuse of the cooling water are ensured. For the current situation, it can reduce the consumption of cooling water during the production process of hexamethylenediamine, play a role in saving resources and reducing energy consumption, and has good economic benefits and development space.

[0030] The above has described in detail the preferred specific embodiments and examples of the utility model in conjunction with the attached drawings. However, the utility model is not limited to the above embodiments and examples. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the concept of the utility model.

Claims

1. A cooling water recycling system in the production process of hexamethylenediamine, characterized in that: It comprises a pipeline system, a control valve regulating system, a first cooling water circulation pump (13), a second cooling water circulation pump (14), a first cooling water heat exchanger (15) and a second cooling water heat exchanger (16); The pipeline system comprises a 60°C desalted water supply pipeline (1), a 60°C desalted water return pipeline (10), a low-pressure steam pipeline (2), a 45°C desalted water return pipeline (3), a steam condensate pipeline (4), a 45°C desalted water supply pipeline (5), a 45°C desalted water circulation pipeline (6), a cooling water circulation pump inlet pipeline (7), a circulating water supply pipeline (11), a circulating water return pipeline (12) and a desalted water replenishment pipeline (8); The control valve regulating system comprises a 60°C desalted water temperature control regulating valve (17), a 45°C desalted water pressure control regulating valve (18), and a 45°C desalted water temperature control regulating valve (19); The 45°C desalted water return pipeline (3) is connected to the first cooling water heat exchanger (15); the 45°C desalted water in the 45°C desalted water return pipeline (3) is heated by the first cooling water heat exchanger (15) using the low-pressure steam pipeline (2) and then connected to the 60°C desalted water supply pipeline (1) for recycling as a 60°C desalted water supply system; the temperature of the first cooling water heat exchanger (15) is controlled by a 60°C desalted water temperature control regulating valve (17); the steam condensate generated after heat exchange in the low-pressure steam pipeline (2) is sent to the steam condensate pipeline network through the steam condensate pipeline (4); The 60°C desalted water return pipeline (10) is connected to the second cooling water heat exchanger (16); the 60°C desalted water in the 60°C desalted water return pipeline (10) is cooled by heat exchange with the circulating water supply pipeline (11) through the second cooling water heat exchanger (16); and then connected to the cooling water circulation pump inlet pipeline (7) for recycling as the 45°C desalted water supply system; the temperature of the second cooling water heat exchanger (16) is controlled by the 45°C desalted water temperature control regulating valve (19); The desalted water replenishment pipeline (8) is arranged on the cooling water circulation pump inlet pipeline (7) at the outlet end of the second cooling water heat exchanger (16) to replenish the insufficient flow in the cooling water circulation pump inlet pipeline (7).

2. A cooling water recycling system in the production process of hexamethylenediamine as claimed in claim 1, characterized in that: The first cooling water circulation pump (13) and the second cooling water circulation pump (14) are arranged in parallel, and the working states are one normal and one standby. The use state of the first cooling water circulation pump (13) and the second cooling water circulation pump (14) can be switched at any time to ensure continuous and stable operation of the system.

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