An energy-saving low-temperature desalination and dehydration device

Abstract

This utility model discloses an energy-saving low-temperature desalination and dehydration device, relating to the technical field of desalination and dehydration equipment. It includes a vacuum evaporator and a feed inlet: the feed inlet is located above the vacuum evaporator. After the concentrated water discharged from the membrane separation component of this energy-saving low-temperature desalination and dehydration device enters the crystallization reactor, a second motor drives the drive shaft to rotate, causing the wall-scraping agitator to operate continuously within the crystallization reactor. This agitation promotes uniform crystallization of salts in the solution, preventing disordered crystal growth due to localized supersaturation, thus improving crystallization efficiency and purity. Furthermore, the outer end of the wall-scraping agitator moves closely against the inner wall of the crystallization reactor, effectively preventing crystals from adhering to the reactor wall and forming scale, thus avoiding impact on the reactor's heat transfer efficiency and subsequent cleaning difficulty. This ensures uniform solid-liquid distribution of the mixed liquid entering the centrifugal separator, providing favorable conditions for subsequent solid-liquid separation, thereby guaranteeing the efficient and stable operation of the entire desalination and dehydration process.

Description

Technical Field

[0001] This utility model relates to the technical field of desalination and dehydration equipment, specifically an energy-saving low-temperature desalination and dehydration device. Background Technology

[0002] Desalination and dehydration equipment is a specialized device used to separate and remove salt and water from liquids for purification, recycling, or resource reuse. Its core function is to reduce the salt and water content in liquids through physical, chemical, or mechanical means to meet the needs of different industries for material purity, emission standards, or resource recovery. In industrial production, seawater desalination, and other fields, the desalination and dehydration treatment of high-salt wastewater and saline bodies is crucial.

[0003] However, existing desalination and dehydration devices still have certain problems:

[0004] Existing electrostatic desalting and dehydration tanks, such as the one described in application number CN200610018082.8 for oil fields and refineries, are mainly used to solve the problem of excessive oil content in the drainage caused by fluctuations or disturbances at the oil-water interface in existing electrostatic desalting and dehydration tanks. The electrostatic desalting and dehydration tank of this invention has at least three sets of stabilizing drainers along the axial direction of the tank body in the lower part of the tank body. Each set of stabilizing drainers consists of a metal plate and a grid. The metal plate is perpendicular to the axial direction of the tank body, and its two ends are connected to the inner wall of the tank body. A distance is left between the bottom of the metal plate and the bottom of the inner wall of the tank body for the flow of sedimented water. The grid is located on top of the metal plate and is composed of metal strips perpendicular to the metal plate.

[0005] Most existing desalination and dehydration devices use high-temperature evaporation processes, which have problems such as high energy consumption, easy scaling of equipment, and high operating costs. Although some existing desalination and dehydration devices have reduced energy consumption to some extent, the scale that forms inside cannot be effectively removed in the long term, affecting the normal operation of the equipment and reducing its stability.

[0006] Therefore, we propose an energy-saving low-temperature desalination and dehydration device to solve the problems mentioned above. Utility Model Content

[0007] The purpose of this utility model is to provide an energy-saving low-temperature desalination and dehydration device to solve the problems mentioned in the background art, which mostly adopt high-temperature evaporation process. This method has problems such as high energy consumption, easy scaling of equipment, and high operating costs. Although some existing desalination and dehydration equipment has reduced energy consumption to a certain extent, the scale that forms inside cannot be effectively removed in the long term, which affects the normal operation of the equipment and reduces the stability of the equipment.

[0008] To achieve the above objectives, this utility model provides the following technical solution: an energy-saving low-temperature desalination and dehydration device, comprising a vacuum evaporation kettle and a feed inlet:

[0009] The vacuum evaporator has a feed inlet and a steam connection port at its top. It also has a discharge port at its bottom. A spiral wound tube heat exchanger is located on one side of the vacuum evaporator, with a hot-side inlet, a cold-side inlet, and a hot-side outlet on its exterior. The hot-side outlet of the spiral wound tube heat exchanger is connected to a condensate tank via a pipe. A discharge port is located on one side of the condensate tank. A membrane separation assembly is located on one side of the vacuum evaporator. A crystallization reactor is located on one side of the membrane separation assembly. A second motor is installed at the top of the crystallization reactor, and a drive shaft is fixed to the output end of the second motor. A wall-scraping agitator is installed on the outer surface of the drive shaft. A slag discharge port is connected to the bottom of the crystallization reactor and is connected to a centrifugal separator. A centrifugal separator is located on one side of the crystallization reactor.

[0010] By adopting the above technical solution, the boiling point of the liquid is reduced under negative pressure in the vacuum evaporator to achieve low-temperature evaporation. The generated steam is used to preheat the feed liquid by recovering heat through a spiral wound tube heat exchanger. The condensate is collected in the condensate tank. The concentrated liquid after evaporation passes through the membrane separation component, the crystallization reactor and the centrifuge in sequence to further separate salt and water, so as to achieve the purpose of efficient desalination and dehydration. This effectively solves the problems of high energy consumption and easy scaling of traditional equipment, and improves the processing efficiency and equipment stability.

[0011] Preferably, a first motor is installed at the upper end of the vacuum evaporator, a stirring shaft is fixed at the output end of the first motor, and the stirring shaft is movably connected to the vacuum evaporator through a bearing. A spiral stirring paddle is fixed on the outer surface of the stirring shaft, and a heating wire is embedded in the inner wall of the vacuum evaporator.

[0012] Using the above technical solution, inside the vacuum evaporator, the first motor drives the stirring shaft and rotates the spiral stirring paddle to mix the liquid evenly and ensure that the liquid is heated evenly. The heating wire embedded in the inner wall of the vacuum evaporator is energized and heats up, and the liquid is heated and evaporated at low temperature in a vacuum environment. The stirring and heating work together to accelerate the vaporization of water, improve the desalination and dehydration efficiency, and at the same time reduce the scaling problem caused by local overheating.

[0013] Preferably, the hot-side inlet of the spiral wound tube heat exchanger is connected to the steam connection port of the vacuum evaporator via a steam pipe, the hot-side outlet is connected to the condensate tank via a pipe, and the cold-side inlet is connected to the feed port via a pipe.

[0014] Using the above technical solution, the hot-side inlet of the spiral wound tube heat exchanger is connected to the steam connection port of the vacuum evaporator, so that the steam generated by evaporation enters the hot side to release latent heat, flows into the condensate tank through the hot-side outlet and is condensed and collected, and the cold-side inlet is connected to the feed inlet, so that the liquid to be treated enters the cold side to absorb the heat of the steam to achieve preheating. Through the countercurrent flow heat exchange on the hot and cold sides, the heat of the steam is effectively recovered for the preheating of the liquid, reducing the overall energy consumption of the device and improving the energy utilization efficiency.

[0015] Preferably, the vacuum evaporator is connected to the membrane separation assembly via a discharge port connecting pipe, and the outer side of the membrane separation assembly is connected to a concentrate end, the other end of which is connected to the top of the crystallization reactor. The outer side of the membrane separation assembly is connected to a product water end, which is connected to a condensate tank via a pipe.

[0016] Using the above technical solution, the concentrated liquid discharged from the vacuum evaporator enters the membrane separation unit through the discharge port. Utilizing the selective permeability of the membrane, the separated fresh water is transported to the condensate tank for recycling at the product water end, while the concentrated liquid with salt retention is sent to the crystallization reactor at the concentrate water end. The combined use of membrane separation and crystallization reactor can realize the graded concentration and crystallization separation of salt, improve desalination efficiency, reduce the processing load of the crystallization unit, and reduce overall energy consumption.

[0017] Preferably, the centrifugal separator is provided with a liquid phase outlet and a solid phase outlet on its outer side, and the liquid phase outlet is connected to the feed inlet through a pipe.

[0018] Using the above technical solution, the centrifugal separator uses the centrifugal force generated by high-speed rotation to separate the mixed liquid from the crystallization reactor. The separated salt crystals are discharged from the solid phase outlet, while the brine from the liquid phase outlet is returned to the feed inlet of the vacuum evaporator through a pipeline to achieve recycling, improve the salt recovery rate, reduce material waste, reduce the load on subsequent processing stages, and improve the overall desalination and dehydration efficiency of the device.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. After the concentrated water discharged from the membrane separation unit enters the crystallization reactor, the second motor drives the drive shaft to rotate, so that the wall scraper agitator operates continuously in the crystallization reactor. The agitation promotes the uniform crystallization and precipitation of salt in the solution, avoids disordered crystal growth due to local supersaturation, improves crystallization efficiency and crystal purity. Moreover, the outer end of the wall scraper agitator moves in close contact with the inner wall of the crystallization reactor, which can effectively prevent crystals from adhering to the reactor wall and forming a scale layer, avoid affecting the heat transfer efficiency of the reactor and the difficulty of subsequent cleaning, and ensure that the solid-liquid distribution of the mixed liquid entering the centrifugal separator is uniform, providing good conditions for the subsequent solid-liquid separation stage, thereby ensuring the efficient and stable operation of the entire desalination and dehydration process.

[0021] 2. The liquid to be treated enters the vacuum evaporator through the feed inlet. The first motor on the vacuum evaporator starts and drives the stirring shaft and spiral stirring paddle to rotate, so that the liquid in the vacuum evaporator is mixed evenly. The heating wire embedded in the inner wall heats the liquid at low temperature in a vacuum environment. Combined with the stirring structure, the liquid is heated evenly, the water vaporization is accelerated, and the desalination and dehydration efficiency is improved. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the external structure of this utility model from the front view;

[0023] Figure 2 This is a schematic diagram of the internal stirring structure of the vacuum evaporator of this utility model;

[0024] Figure 3 This is a schematic diagram of the internal descaling structure of the crystallization reactor of this utility model;

[0025] Figure 4 This is a schematic diagram of the heat recovery structure of this utility model;

[0026] Figure 5 This is a schematic diagram of the desalination and dehydration structure of this utility model.

[0027] In the diagram: 1. Vacuum evaporator; 2. Feed inlet; 3. Steam connection port; 4. First motor; 5. Stirring shaft; 6. Spiral agitator; 7. Heating wire; 8. Discharge port; 9. Spiral wound tube heat exchanger; 10. Hot side inlet; 11. Cold side inlet; 12. Hot side outlet; 13. Condensate tank; 14. Discharge port; 15. Membrane separation unit; 16. Concentrate end; 17. Product water end; 18. Crystallization reactor; 19. Second motor; 20. Drive shaft; 21. Wall scraper agitator; 22. Slag discharge port; 23. Centrifuge; 24. Liquid phase outlet; 25. Solid phase outlet. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0029] Please see Figures 1-5This utility model provides a technical solution: an energy-saving low-temperature desalination and dehydration device, including a vacuum evaporator 1 and a feed inlet 2; the feed inlet 2 is provided above the vacuum evaporator 1, a steam connection port 3 is provided above the vacuum evaporator 1, a discharge port 8 is provided at the bottom of the vacuum evaporator 1, a spiral wound tube heat exchanger 9 is provided on one side of the vacuum evaporator 1, the spiral wound tube heat exchanger 9 is provided with a hot side inlet 10, a cold side inlet 11 and a hot side outlet 12 on the outside, and the hot side outlet 12 of the spiral wound tube heat exchanger 9 is connected to a condenser via a pipe. A water tank 13 and a condensate tank 13 are provided with a discharge port 14 on one side. A membrane separation component 15 is provided on one side of the vacuum evaporator 1. A crystallization reactor 18 is provided on one side of the membrane separation component 15. A second motor 19 is installed at the upper end of the crystallization reactor 18. A drive shaft 20 is fixed to the output end of the second motor 19. A wall scraper agitator 21 is installed on the outer surface of the drive shaft 20. A slag discharge port 22 is connected to the bottom of the crystallization reactor 18 and is connected to a centrifugal separator 23. A centrifugal separator 23 is provided on one side of the crystallization reactor 18. A first motor 4 is installed at the upper end of the vacuum evaporator 1. A stirring shaft 5 is fixed to the output end of the first motor 4 and is movably connected to the vacuum evaporator 1 through a bearing. A spiral stirring paddle 6 is fixed to the outer surface of the stirring shaft 5. An electric heating wire 7 is embedded in the inner wall of the vacuum evaporator 1. The hot-side inlet 10 of the spiral wound tube heat exchanger 9 is connected to the steam connection port 3 of the vacuum evaporator 1 via a steam pipe, and the hot-side outlet 12 is connected to the condensate tank 13 via a pipe, while the cold-side inlet 11 is connected to the feed inlet 2 via a pipe. The vacuum evaporator 1 is connected to the membrane separation assembly 15 via a discharge port 8, and the outer side of the membrane separation assembly 15 is connected to a concentrate end 16, the other end of which is connected to the top of the crystallization reactor 18. The outer side of the membrane separation assembly 15 is connected to a product water end 17, which is connected to the condensate tank 13 via a pipe. The centrifuge 23 has a liquid phase outlet 24 and a solid phase outlet 25 on its outer side, and the liquid phase outlet 24 is connected to the feed inlet 2 via a pipe.

[0030] The liquid to be processed enters the vacuum evaporator 1 through the feed inlet 2. The first motor 4 on the vacuum evaporator 1 starts and drives the stirring shaft 5 and the spiral stirring paddle 6 to rotate, so that the liquid in the vacuum evaporator 1 is mixed evenly. The heating wire 7 embedded in the inner wall heats the liquid at low temperature in a vacuum environment. Combined with the stirring structure, the liquid is heated evenly, which accelerates the vaporization of water and improves the desalination and dehydration efficiency. The steam generated by vaporization is discharged from the steam connection port 3 and enters the heat exchanger through the hot side inlet 10 of the spiral wound tube heat exchanger 9. After releasing the latent heat, it flows into the condensate tank 13 from the hot side outlet 12. The cold side inlet 11 is connected to the feed inlet 2, which can use the waste heat of the steam to preheat the feed, reduce the overall energy consumption of the device, and improve the energy utilization efficiency. Vacuum evaporation The concentrated liquid discharged from the bottom discharge port 8 of the reactor 1 enters the membrane separation unit 15. The fresh water separated by the membrane separation unit 15 flows into the condensate tank 13 through the product water end 17, while the concentrated water enters the crystallization reactor 18 through the concentrated water end 16. Under the action of the wall scraper agitator 21 driven by the second motor 19, the salt crystallization is promoted. The crystallized mixture enters the centrifuge 23 through the slag discharge port 22. The separated salt crystals are discharged from the solid phase outlet 25, and the brine is returned to the feed port 2 for further processing through the liquid phase outlet 24. Thus, with the synergistic effect of each component, efficient desalination and dehydration can be achieved in a low-temperature environment. At the same time, energy consumption is reduced, resource utilization is improved, equipment efficiency is increased, and equipment stability is enhanced by using heat recovery and recycling.

[0031] Working principle: For this type of energy-saving low-temperature desalination and dehydration device, the liquid to be treated enters the vacuum evaporator 1 through the feed inlet 2. The liquid is heated at low temperature in a vacuum environment to accelerate the vaporization of water. The generated steam is discharged from the steam connection port 3 and enters through the hot side inlet 10 of the spiral wound tube heat exchanger 9. After releasing latent heat, it flows into the condensate tank 13 from the hot side outlet 12. At the same time, the cold side inlet 11 is connected to the feed inlet 2 to preheat the feed using the waste heat of steam, reducing energy consumption. The concentrated liquid discharged from the bottom discharge port 8 of the vacuum evaporator 1 enters the membrane separation component 15. The separated fresh water flows into the condensate tank 13 through the product water end 17. The concentrated water enters the crystallization reactor 18 through the concentrated water end 16. The mixture after stirring and crystallization enters the centrifuge 23 through the slag discharge port 22. The separated salt crystals are discharged from the solid phase outlet 25. The brine flows back to the feed inlet 2 for further treatment through the liquid phase outlet 24. This achieves efficient desalination and dehydration, heat recovery and material recycling in a low-temperature environment, reducing energy consumption and improving resource utilization efficiency.

[0032] This completes a series of tasks. The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0033] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An energy-saving low-temperature desalination and dehydration device, comprising a vacuum evaporator (1) and a feed inlet (2), characterized in that: The vacuum evaporator (1) has a feed inlet (2) at its top and a steam connection port (3) at its top. The vacuum evaporator (1) also has a discharge port (8) at its bottom. A spiral wound tube heat exchanger (9) is located on one side of the vacuum evaporator (1). The spiral wound tube heat exchanger (9) has a hot-side inlet (10), a cold-side inlet (11), and a hot-side outlet (12) on its exterior. The hot-side outlet (12) of the spiral wound tube heat exchanger (9) is connected to a condensate tank (13) via a pipe. A discharge port (14) is located on one side of the condensate tank (13). A membrane separation assembly (15) is provided on one side of the vacuum evaporator (1), and a crystallization reactor (18) is provided on one side of the membrane separation assembly (15). A second motor (19) is installed at the upper end of the crystallization reactor (18), and a drive shaft (20) is fixed at the output end of the second motor (19). A wall scraper (21) is installed on the outer surface of the drive shaft (20). A slag discharge port (22) is connected to the bottom of the crystallization reactor (18), and the slag discharge port (22) is connected to a centrifugal separator (23). A centrifugal separator (23) is provided on one side of the crystallization reactor (18).

2. The energy-saving low-temperature desalination and dehydration device according to claim 1, characterized in that: The upper end of the vacuum evaporator (1) is equipped with a first motor (4), the output end of the first motor (4) is fixed with a stirring shaft (5), and the stirring shaft (5) is movably connected to the vacuum evaporator (1) through a bearing. The outer surface of the stirring shaft (5) is fixed with a spiral stirring paddle (6), and the inner sidewall of the vacuum evaporator (1) is inlaid with an electric heating wire (7).

3. The energy-saving low-temperature desalination and dehydration device according to claim 1, characterized in that: The hot side inlet (10) of the spiral wound tube heat exchanger (9) is connected to the steam connection port (3) of the vacuum evaporator (1) through a steam pipe, and the hot side outlet (12) is connected to the condensate tank (13) through a pipe, and the cold side inlet (11) is connected to the feed inlet (2) through a pipe.

4. The energy-saving low-temperature desalination and dehydration device according to claim 1, characterized in that: The vacuum evaporator (1) is connected to the membrane separation unit (15) through the discharge port (8) and the outside of the membrane separation unit (15) is connected to the concentrate end (16), and the other end of the concentrate end (16) is connected to the top of the crystallization reactor (18). The outside of the membrane separation unit (15) is connected to the product water end (17), and the product water end (17) is connected to the condensate tank (13) through the pipe.

5. The energy-saving low-temperature desalination and dehydration device according to claim 1, characterized in that: The centrifuge (23) is provided with a liquid phase outlet (24) and a solid phase outlet (25) on its outer side, and the liquid phase outlet (24) is connected to the feed inlet (2) through a pipe.

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