Multi-stage evaporation heat compression type energy-saving distilled water preparation system

Abstract

The application provides a multi-stage evaporation heat compression energy-saving distilled water preparation system, which comprises a preheating system for preheating raw water to a set temperature, an evaporation separation system connected with the preheating system through a pipeline, the evaporation separation system comprising a main evaporator, an atomized liquid membrane device and a ladder type refining separator, wherein the atomized liquid membrane device and the ladder type refining separator are arranged in the main evaporator, and a distilled water collecting system connected with the evaporation separation system through a pipeline and used for collecting distilled water. The atomized liquid membrane device and the ladder type refining separator are used for further separating distilled water, so that the endotoxin in the produced water and the conductivity of the produced water are reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of distillation, and is particularly suitable for preparing distilled water in the fields of medicine, food, seawater desalination, scientific research experiments, and the like, and particularly relates to a multi-stage evaporation heat compression type distilled water preparation system. BACKGROUND

[0002] Distilled water is pure water prepared by distillation, and does not contain impurities, and can be used for drinking and is also widely used in the fields of chemistry, biology, medicine, and the like. With the development of science and technology and the improvement of people's living standards, pharmaceutical factories, hospitals, and scientific research units gradually increase the quality requirements for water.

[0003] For example, application No. 201710155851.7, a kind of external heat compression type distilled water preparation system, uses a silk screen separation device to generate pure steam, separates the pure steam, and then uses steam-water separation and non-condensable gas discharge to reduce the endotoxin of the produced water and the conductivity of the produced water, but the separation time is short and the separation effect is unstable. SUMMARY

[0004] To solve the above technical problems, the present application provides a multi-stage evaporation heat compression type energy-saving distilled water preparation system, which uses an atomized liquid membrane device and a stepped refining separator to improve the quality of distilled water and reduce the endotoxin of the produced water and the conductivity of the produced water.

[0005] Specifically, the present application discloses a multi-stage evaporation heat compression type energy-saving distilled water preparation system, which comprises a preheating system for preheating raw water to a set temperature, an evaporation separation system connected to the preheating system through a pipeline, the evaporation separation system comprising a main evaporator, an atomized liquid membrane device, and a stepped refining separator, the atomized liquid membrane device and the stepped refining separator being arranged inside the main evaporator, and a distilled water collection system connected to the evaporation separation system through a pipeline, the distilled water collection system being used for collecting distilled water.

[0006] By using the above scheme, the present distilled water preparation system uses a preheating system to heat the raw water to a set temperature, and then uses an atomized liquid membrane device and a stepped refining separator to evaporate and separate the raw water. The atomized liquid membrane device reasonably distributes the raw water on the heat exchanger to achieve the best water distribution effect. The stepped refining separator separates the pure steam multiple times to naturally settle small droplets containing bacterial endotoxin and other impurities under the action of gravity, thereby reducing the endotoxin of the produced water and the conductivity of the produced water and improving the quality of the distilled water.

[0007] Furthermore, the atomizing liquid film device includes an atomizer and a U-shaped heat exchange tube, wherein the atomizer is evenly distributed above the U-shaped heat exchange tube, and the U-shaped heat exchange tube is installed inside the main evaporator.

[0008] By adopting the above scheme, the atomizers evenly distributed above the U-shaped heat exchange tubes avoid the phenomenon of local drying of the tube bundle due to uneven water distribution, reduce scaling of the tube bundle, improve heat transfer efficiency, and achieve the best water distribution effect.

[0009] Furthermore, the stepped refining separator includes a guide plate that divides the stepped refining separator into several layers.

[0010] By adopting the above scheme, the guide plate divides the stepped refiner into several layers, adjusting the degree of steam refinement and separation.

[0011] Furthermore, the guide plate is provided with several guide holes for steam flow, and the guide plates are installed alternately in the stepped fine separator, forming a flow channel that restricts steam flow between the guide plates and the guide holes.

[0012] By adopting the above scheme, the guide plates are arranged alternately in opposite directions, and the guide plates and guide holes form a serpentine channel, which maximizes the stroke of pure steam in the stepped fine separator and improves the separation effect of pure steam.

[0013] Furthermore, the preheating system includes a primary raw water heat exchanger, a secondary raw water heat exchanger, a tertiary raw water heat exchanger, a quaternary raw water heat exchanger, and a quinary raw water heat exchanger. The primary raw water heat exchanger is connected to the secondary and tertiary raw water heat exchangers, and the outlet of the secondary raw water heat exchanger is connected to the inlet of the quinary raw water heat exchanger.

[0014] By adopting the above scheme, the preheating system uses multiple heat exchangers, and the heat of the preheated raw water pure steam is recycled as a heat source, saving the heat required for the evaporation of raw water, and at the same time eliminating the need for cooling water for secondary steam condensation.

[0015] Furthermore, the distilled water collection system includes a distilled water collection tank, a distilled water delivery pump connected to the distilled water collection tank, and a non-condensable gas heat recovery system. The distilled water collection tank is equipped with a secondary separation device, and a distilled water filter is installed below the secondary separation device.

[0016] By adopting the above scheme, the distilled water separated by evaporation in the main evaporator enters the distilled water collection tank through pipelines. The non-condensable gases contained in the distilled water are collected by a secondary separation device. The collected non-condensable gases are then subjected to secondary heat recovery to provide waste heat exchange for the main evaporator.

[0017] Furthermore, the preheating system is provided with two industrial steam inlets, one of which is connected to the shell-side inlet of the fourth-stage feed water heat exchanger, and the other is connected to the shell-side inlet of the second-stage feed water heat exchanger.

[0018] By adopting the above scheme, the industrial steam inlet is the heat exchange medium of the system. The main function of the fourth-stage feed water heat exchanger is to exchange heat during the initial start-up of the system. When the system reaches equilibrium operation, the fourth-stage feed water heat exchanger stops or intermittently starts to provide auxiliary heating. The second-stage feed water heat exchanger preheats the feed water for a second time. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0020] Figure 1 This is a schematic diagram of a multi-stage evaporation-type thermal compression energy-saving distilled water preparation system;

[0021] Figure 2 This is a schematic diagram of the atomizing liquid film device in a multi-stage evaporation thermal compression energy-saving distilled water preparation system;

[0022] Figure 3 This is a schematic diagram of a stepped fine separator in a multi-stage evaporation-type thermal compression energy-saving distilled water preparation system.

[0023] The reference numerals in the attached diagram are as follows: 1. Primary feedwater heat exchanger; 2. Secondary feedwater heat exchanger; 3. Tertiary feedwater heat exchanger; 4. Main evaporator; 5. Quaternary feedwater heat exchanger; 6. Fifth-stage feedwater heat exchanger; 7. Steam compressor; 8. Distilled water collection tank; 9. Industrial steam regulating valve; 10. Feedwater regulating valve; 11. Feedwater circulation pump; 12. Atomizer; 13. Step-type fine separator; 14. Distilled water delivery pump; 15. Distilled water filter; 16. Distilled water outlet regulating valve. 17. Industrial steam regulating valve, 18 and 19. Condensate drain valve, 20. Drain valve, 21. Concentrated water drain valve, 22. Secondary separation device, 23. Flow regulating valve, 24. Distilled water detection device, 41. U-shaped heat exchange tube, 131. Guide plate, 132. Guide hole, A1 and A2. Industrial steam inlet, B1 and B2. Raw water inlet, C. Concentrated water outlet, D. Unqualified distilled water outlet, E. Qualified distilled water outlet, F. Non-condensable gas outlet, G. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings.

[0025] like Figure 1As shown, this invention provides a multi-stage evaporation-type thermal compression energy-saving distilled water preparation system, including a preheating system for preheating raw water to a set temperature; an evaporation separation system connected to the preheating system via pipelines, the evaporation separation system including a main evaporator 4, an atomizing liquid film device, and a stepped fine separator 13, both of which are located inside the main evaporator 4; and a distilled water collection system connected to the evaporation separation system via pipelines for collecting distilled water.

[0026] The multi-stage preheating system for raw water can also be called a waste heat reuse system. It utilizes the waste heat generated within the system to preheat the raw water to the required temperature, resulting in high thermal energy utilization, low steam consumption, and high feed water utilization. The raw water undergoes fine separation of pure steam through an atomizing liquid film device and a stepped fine separator 13. The atomizing liquid film device ensures that the raw water is evenly distributed on the U-shaped heat exchange tubes 41, achieving optimal water distribution. The stepped fine separator 13 performs multiple fine separations of pure steam, causing small droplets containing bacterial endotoxins and other impurities to settle naturally under gravity, reducing endotoxins and conductivity in the product water and improving the quality of distilled water.

[0027] like Figure 2 As shown, in some embodiments of the present invention, the atomizing liquid film device includes an atomizer 12 and a U-shaped heat exchange tube 41. The atomizer 12 is evenly distributed above the U-shaped heat exchange tube 41. The U-shaped heat exchange tube 41 is installed in the main evaporator 4. The inlet of the atomizer 12 is connected to the outlet of the raw material water circulation pump 11. The inlet of the U-shaped heat exchange tube 41 is connected to the outlet of the steam compressor 7. The outlet of the U-shaped heat exchange tube 41 is connected to the inlet of the secondary separation device 22 in the distilled water collection tank 8.

[0028] Raw water flows out from the pipe below the main evaporator 4 and enters the raw water circulation pump 11. The raw water circulation pump 11 delivers the raw water to the atomizer 12, which sprays the raw water evenly onto the U-shaped heat exchange tubes 41, evaporating the raw water upon contact with the tubes. The evenly distributed atomizers 12 above the U-shaped heat exchange tubes 41 prevent localized drying of the tube bundle due to uneven water distribution, reduce scaling, improve heat transfer efficiency, and achieve optimal water distribution.

[0029] In some embodiments of the present invention, the stepped fine separator 13 includes a guide plate 131, which divides the stepped fine separator 13 into several layers. The inlet of the stepped fine separator 13 is connected to the cavity of the main evaporator 4, and the outlet is connected to the inlet of the steam compressor 7. The pure steam formed after the raw water passes through the atomizing liquid film device enters the stepped fine separator 13.

[0030] With the arrangement of the guide plate 131 in this embodiment, the guide plate 131 divides the stepped fine separator 13 into several layers, and the number and spacing of the guide plate 131 can be adjusted according to the needs.

[0031] like Figure 3 As shown, in some embodiments of the present invention, the guide plate 131 is provided with a plurality of guide holes 132 for steam flow. The guide plate 131 is installed alternately in the stepped fine separator 13, and a flow channel restricting steam flow is formed between the guide plate 131 and the guide holes 132.

[0032] With the arrangement of the guide plate 131 in this embodiment, pure steam forms a serpentine channel through the guide plate 131 and the guide hole 132, maximizing the stroke of pure steam in the stepped separator 13 and improving the separation effect of pure steam.

[0033] In some embodiments of the present invention, the preheating system includes a primary feed water heat exchanger 1, a secondary feed water heat exchanger 2, a tertiary feed water heat exchanger 3, a quaternary feed water heat exchanger 5, and a quinary feed water heat exchanger 6. The primary feed water heat exchanger 1 is connected to the secondary feed water heat exchanger 2 and the tertiary feed water heat exchanger 3, and the outlet of the secondary feed water heat exchanger 2 is connected to the inlet of the quinary feed water heat exchanger 6.

[0034] The inlet of the tube side of the primary feed water heat exchanger 1 is connected to the feed water inlet C, and the outlet is connected to the flow regulating valve 23. The flow regulating valve 23 divides the feed water into two parts: one part enters the tube side inlet of the secondary feed water heat exchanger 2, and the other part enters the shell side inlet of the tertiary feed water heat exchanger 3. The heat exchange medium of the primary feed water heat exchanger 1 is distilled water concentrate. The distilled water concentrate is discharged from the concentrate drain valve 21 and flows into the shell side inlet of the primary feed water heat exchanger 1, and then discharged from the outlet to the concentrate discharge port D.

[0035] The tube-side inlet of the secondary feed water heat exchanger 2 is connected to the flow regulating valve 23, and the tube-side outlet is connected to the inlet of the fifth-stage feed water heat exchanger 5. The industrial steam inlet A2 is connected to the shell-side inlet of the secondary feed water heat exchanger 2 through the industrial steam regulating valve 17, and then flows out from the shell-side outlet, enters the condensate drain valve 18, and flows out at the industrial steam condensate outlet B2.

[0036] After passing through the primary feed water heat exchanger 1, a portion of the feed water enters the shell-side inlet of the tertiary feed water heat exchanger 3, and after flowing out of the outlet, it enters the tube-side inlet of the secondary feed water heat exchanger 2. The distilled water collected by the distilled water collection tank 8 enters the tube-side inlet of the tertiary feed water heat exchanger 3 through the distilled water transfer pump 14. The tube-side outlet is equipped with a non-conforming distilled water discharge port E and a conforming distilled water discharge port F. The distilled water flows through the distilled water detection device 24 to detect the distilled water. Conforming distilled water is discharged from the conforming distilled water discharge port F, while non-conforming distilled water is discharged from the non-conforming distilled water discharge port E.

[0037] Industrial steam inlet A1 enters the fourth-stage feed water heat exchanger 5 through industrial steam regulating valve 9, and after flowing out of the outlet, it passes through condensate drain valve 19 and flows out through industrial steam condensate outlet B1. The main function of the fourth-stage feed water heat exchanger 5 is for heat exchange during the initial start-up of the system. When the system reaches equilibrium operation, the fourth-stage feed water heat exchanger 5 stops or intermittently starts its auxiliary heating function.

[0038] The raw water flows out of the tube side outlet of the secondary raw water heat exchanger 2 and enters the inlet of the fifth-stage raw water heat exchanger 6. After heat exchange, it flows out of the outlet and enters the bottom of the main evaporator 4 for the next process.

[0039] Through the preheating system configuration in this embodiment, the heat medium in the preheating system exchanges heat with the raw water to preheat it. The waste heat generated by the entire system is used to preheat the raw water multiple times, effectively reducing heat loss. When the equipment is operating stably, only a small amount of industrial steam needs to be added, which can compensate for the heat loss carried away by the discharged distilled water and non-condensable gases. Therefore, this preparation system can achieve low-cost distilled water production.

[0040] In some embodiments of the present invention, the preparation system includes a distilled water collection system, which comprises a distilled water collection tank 8, a distilled water delivery pump 14 connected to the distilled water collection tank 8, and a non-condensable gas heat recovery system. The distilled water collection tank 8 contains a secondary separation device 22, below which is a distilled water filter 15. The inlet of the secondary separation device 22 is connected to a plate box at the outlet of the U-shaped heat exchange tube 41. The heat generated during the secondary separation flows out through the heat outlet and into the plate box at the inlet of the U-shaped heat exchange tube 41, providing heat to the U-shaped heat exchange tube 41. The non-condensable gas generated during the secondary separation flows into the main evaporator 4 through the outlet above the secondary separation device 22.

[0041] With the distilled water collection system of this embodiment, the distilled water separated by evaporation from the main evaporator 4 enters the distilled water collection tank 8 through a pipeline. The non-condensable gases contained in the distilled water are collected by the secondary separation device 22. The collected non-condensable gases undergo secondary heat recovery to provide waste heat exchange for the main evaporator 4. After that, they are discharged through the five-stage raw water heat exchanger 6.

[0042] The working method of this invention is as follows: the raw water enters through the raw water inlet C, passes through the raw water regulating valve 10 and enters the tube side of the first-stage raw water heat exchanger 1. After flowing out through the outlet, it enters the flow regulating valve 23. Part of it flows into the tube side inlet of the second-stage raw water heat exchanger 2, and the other part flows into the shell side inlet of the third-stage raw water heat exchanger 3 for heat exchange in the third-stage raw water heat exchanger 3. Industrial steam inlet A2 exchanges heat with the secondary feed water heat exchanger 2. The feed water flowing into the tube-side inlet of the secondary feed water heat exchanger 2 passes through the fifth-stage feed water heat exchanger 6 and enters the bottom of the main evaporator 4. Then it flows into the feed water circulation pump 11, which pressurizes the feed water and sends it to the atomizer 12. The atomizer 12 evenly sprays the feed water onto the U-shaped heat exchange tubes 41. The evaporated steam enters the stepped fine separator 13, and after being compressed by the steam compressor 7, it is transmitted to the plate box on the right side of the main evaporator. It then enters the inlet of the U-shaped heat exchange tubes 41 and flows out of the outlet, where it exchanges heat with the fifth-stage feed water heat exchanger 6 in the plate box. The heated water then flows into the secondary separation device 22 in the distilled water collection tank 8 for secondary separation. The heat and non-condensable gas generated after separation enter the U-shaped heat exchange tube 41 and the main evaporator 4 through pipes to provide heat. The collected distilled water is transferred to the tertiary feed water heat exchanger 3 by the distilled water transfer pump 14, and finally flows through the distilled water detection device 24 to test the distilled water. The qualified distilled water is discharged at the qualified distilled water discharge port F. The feed water flowing into the tertiary feed water heat exchanger 3 enters the shell side of the tertiary feed water heat exchanger 3 to exchange heat with the tertiary feed water heat exchanger 3. After the heat exchange is completed, it flows into the tube side of the secondary feed water heat exchanger 2. The drain valve 20 below the main evaporator 4 is used to discharge the feed water in the main evaporator 4.

[0043] For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this invention, and these all fall within the protection scope of this invention.

Claims

1. A multi-stage evaporation heat compression type energy saving distilled water production system, characterized by, The utility model relates to a kind of water distillation system, comprising: Preheating system for preheating raw water to set temperature; Evaporation separation system connected with preheating system by pipeline, the evaporation separation system includes main evaporator (4), atomizing liquid film device, stepped refining separator (13), and the atomizing liquid film device and stepped refining separator (13) are all arranged inside main evaporator (4); Distilled water collection system connected with evaporation separation system by pipeline, the distilled water collection system is used for the collection of distilled water;Wherein, The atomizing liquid film device includes atomizer (12) and U-shaped heat exchange pipe (41), the atomizer (12) is uniformly distributed above U-shaped heat exchange pipe (41), and the U-shaped heat exchange pipe (41) is installed in main evaporator (4); The preheating system includes primary raw water heat exchanger (1), secondary raw water heat exchanger (2), tertiary raw water heat exchanger (3), fourth raw water heat exchanger (5), fifth raw water heat exchanger (6), the primary raw water heat exchanger (1) is connected with secondary raw water heat exchanger (2), tertiary raw water heat exchanger (3), and the water outlet of secondary raw water heat exchanger (2) is connected with the water inlet of fifth raw water heat exchanger (6); The distilled water collection system includes distilled water collection tank (8), distilled water delivery pump (14) connected with distilled water collection tank (8), non-condensable gas heat recovery system, the secondary separation device (22) is arranged in distilled water collection tank (8), and distilled water filter (15) is arranged below the secondary separation device (22); The preheating system is provided with two industrial steam inlets, one industrial steam inlet (A1) is connected with the shell side inlet of fourth raw water heat exchanger (5), and the other industrial steam inlet (A2) is connected with the shell side inlet of secondary raw water heat exchanger (2); The distilled water collected in distilled water collection tank (8) enters the tube side inlet of tertiary raw water heat exchanger (3) through distilled water delivery pump (14), and unqualified distilled water discharge port E and qualified distilled water discharge port F are arranged at the tube side outlet, distilled water flows through distilled water detection device (24) to detect distilled water, and qualified distilled water is discharged from qualified distilled water discharge port F, otherwise, unqualified distilled water is discharged from unqualified distilled water discharge port E; The fourth raw water heat exchanger (5) is used for heat exchange when system is initially started, and when system reaches balanced operation, the fourth raw water heat exchanger (5) stops or intermittently starts auxiliary heating function; The inlet of secondary separation device (22) is communicated with the plate box at the outlet of U-shaped heat exchange pipe (41), heat generated by secondary separation flows out at heat outlet, enters the plate box at the inlet of U-shaped heat exchange pipe (41), provides heat for the U-shaped heat exchange pipe (41), and non-condensable gas generated by secondary separation flows into main evaporator (4) at the outlet above secondary separation device (22). The main evaporator (4) separates distilled water by evaporation, which enters the distilled water collecting tank (8) through a pipeline, collects non-condensable gas contained in the distilled water through the secondary separation device (22), collects the non-condensable gas for secondary heat recovery, provides waste heat exchange for the main evaporator (4), and then discharges through the five-stage raw water heat exchanger (6) for discharge treatment.

2. The multi-stage evaporative heat- compressed energy-efficient water distillation system according to claim 1, wherein, The stepped refinement separator (13) comprises a guide plate (131), and the guide plate (131) divides the stepped refinement separator (13) into a plurality of layers.

3. The multi-stage evaporative heat- compressed energy-efficient water distillation system according to claim 2, wherein, A plurality of guide holes (132) for steam flow are arranged on the guide plate (131), the guide plate (131) is alternately installed inside the stepped refinement separator (13), and a flow channel for limiting steam flow is formed between the guide plate (131) and the guide hole (132).

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