High-salt wastewater evaporation crystallization heat exchange anti-fouling treatment equipment

Abstract

The application discloses a high-salinity wastewater evaporation crystallization heat exchange anti-fouling treatment equipment, and relates to the technical field of wastewater treatment. The equipment comprises a combined tank body for high-salinity wastewater evaporation crystallization and a parallel heat exchange tube bundle assembly for adjusting the heat exchange surface, the high-salinity wastewater raw solution is arranged to flow in the outer space of the parallel heat exchange tube bundle assembly, and the heat transfer medium flows in the inner space of the tube bundle assembly, so that the temperature gradient and the salt concentration gradient of the raw solution are distributed gently, the formation of a strong supersaturation zone at the heat exchange wall surface is avoided, and the heterogeneous nucleation of salt scale on the heat exchange surface is fundamentally inhibited. Meanwhile, the two switchable modes of reverse heat transfer under the top steam inlet state and forward heat transfer under the bottom steam inlet state are arranged, the flow direction of the heat transfer medium is flexibly adjusted according to the concentration change of the raw solution, the reverse heat transfer is utilized to strengthen the efficiency in the evaporation initial stage, and the forward heat transfer is utilized to avoid local supercooling crystallization in the evaporation later stage, so that long-term cleaning of the heat exchange surface is realized in the whole concentration range.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a high-salt wastewater evaporation crystallization heat exchange and scale prevention treatment device. Background Technology

[0002] High-salinity wastewater mainly originates from industries such as chemical, pharmaceutical, coal chemical, and membrane concentration. The key to harmless treatment and resource recovery is evaporation and crystallization. In this process, the wastewater is heated to boiling, and the water continues to evaporate. The salt concentration in the solution gradually increases until it reaches a supersaturated state. In traditional evaporation and crystallization equipment (such as multi-effect evaporators and MVR forced circulation evaporators), the structure of raw liquid flowing inside the tube and steam flowing outside the tube is generally adopted. In this case, the high-temperature heat exchange wall will inevitably be in contact with the continuously concentrated salt solution for a long time. The continuous existence of this solid-liquid interface provides an ideal substrate for heterogeneous nucleation of salts. Compared with homogeneous nucleation that precipitates freely in the solution, the energy required for nucleation on the heat exchange wall is lower. Therefore, scale will preferentially form rapidly on the surface of the heat exchange tube and continue to grow and thicken. That is, the essence of the scaling problem is that the temperature gradient of the heat exchange surface is large. When salts are supersaturated and precipitate, crystal nuclei preferentially form heterogeneous nuclei on the heat exchange surface and continue to grow.

[0003] For example, the MVR evaporator crystallizer disclosed in Chinese invention patent publication number CN218357404U utilizes steam passing through the exhaust pipe into the conveying pipe to complete the steam conversion and collection. That is, it uses the mode of the raw liquid flowing inside the pipe and the steam flowing outside the pipe to complete the evaporation and crystallization treatment of wastewater. In this process, it is difficult to ensure effective scale prevention on the heat exchange surface during the evaporation and crystallization process.

[0004] To address this, the present invention proposes a solution that utilizes a reverse heat exchange structure where the raw liquid flows outside the pipe and the steam flows inside the pipe to prevent clogging and scaling in the evaporator crystallizer. Summary of the Invention

[0005] The technical problem to be solved in this invention is the large temperature gradient on the heat exchange surface caused by the raw liquid flowing inside the pipe and the steam flowing outside the pipe, which leads to continuous scaling. The purpose is to set up a high-salt wastewater evaporation crystallization heat exchange anti-scaling treatment device to solve the above-mentioned technical problem.

[0006] The present invention provides the following apparatus: a high-salt wastewater evaporation crystallization heat exchange and anti-scaling treatment device, comprising a combined tank for high-salt wastewater evaporation crystallization and a parallel heat exchange tube bundle assembly for adjusting the evaporation crystallization heat exchange surface, wherein the combined tank comprises a crystallization tank and an evaporation tank stacked on top of each other;

[0007] The evaporator is vertically inserted into the middle of the crystallizer and connected to the bottom of the crystallizer with a central tube extending to the bottom of the crystallizer; the parallel heat exchange tube bundle assembly includes a rotating U-shaped tube and a near-center ring tube and a lower rotating ring tube that are vertically connected in the crystallizer and the evaporator, and the parallel heat exchange tube bundle assembly is provided with a top steam inlet state and a bottom steam inlet state.

[0008] In the top steam inlet state, the heat transfer medium flows along the direction of the rotary U-shaped tube, the near-center ring tube, and the lower rotary ring tube to achieve reverse heat transfer of the high-salt wastewater solution in the evaporator. In the bottom steam inlet state, the heat transfer medium flows along the direction of the near-center ring tube, the lower rotary ring tube, and the rotary U-shaped tube to achieve forward heat transfer of the high-salt wastewater solution in the evaporator.

[0009] "Reverse heat transfer" means that during the process of the raw liquid entering, the direction of the high-salt wastewater raw liquid is from bottom to top. When the flow direction of the heat transfer medium is opposite to that of the raw liquid, it is called reverse. Similarly, when the flow direction of the heat transfer medium is the same as that of the raw liquid, it is called forward.

[0010] In the forward and reverse heat transfer processes, the high-salt wastewater raw liquid flows "outside the pipe," while the steam, as the heat transfer medium, flows "inside the pipe." The salt concentration gradient and temperature gradient of the raw liquid in the open space are distributed gently over a large range, which fundamentally inhibits the formation of scale on the heat exchange surface.

[0011] Furthermore, a steam compressor is installed on one side of the crystallizer. The steam compressor's outlet end is connected to a steam inlet pipe that communicates with the bottom of the evaporator side. A steam delivery pipe and a steam return pipe are inserted into the steam inlet pipe.

[0012] Furthermore, the upper end of the evaporator is connected to a secondary steam outlet pipe that is connected to the return steam pipe, and the middle part of the evaporator is equipped with a main shaft driven by a motor. The main shaft extends into the interior of the evaporator and the crystallizer, and a rotating lifting assembly is provided together.

[0013] Furthermore, the rotary lifting assembly includes a connecting ring column that communicates with the top of the proximal ring tube. The lower end of the connecting ring column is rotatably connected to a rotating column via a rotating ring. The lower end of the rotating column is connected to the lower rotating ring tube. A stirring rod is installed at the lower end of the main shaft that extends through the rotating column.

[0014] Furthermore, the rotary U-shaped tubes are a circular heat transfer tube bundle structure with the ends connected. The lower end of the outer side of the rotary U-shaped tubes is fitted with a steam circuit pipe that is connected to the steam supply pipe and the steam return pipe. The lower rotary ring tubes are a columnar heat transfer tube bundle structure arranged in a ring. The diameter of the ring formed by the lower rotary ring tubes is the same as the diameter of the evaporator.

[0015] Furthermore, an inlet pipe is connected to the upper side of the crystallizer. The inlet pipe is equipped with a raw liquid pump for pumping in high-salt wastewater raw liquid. When the high-salt wastewater raw liquid enters the crystallizer through the raw liquid pump and inlet pipe, it fills the crystallizer and the liquid level is maintained at the upper part of the evaporator. During the continuous heat exchange process, water evaporates on its liquid surface.

[0016] Furthermore, a main distribution pipe is provided at the lower end of the steam compressor. The distribution end of the main distribution pipe is tangentially connected to the liquid inlet pipe, and a distribution branch pipe is provided on the distribution branch of the main distribution pipe. The distribution branch pipe can divert part of the steam to the bottom of the crystallizer to assist in heating the bottom crystal slurry and maintain the uniformity of the temperature field inside the crystallizer.

[0017] Furthermore, the bottom of the crystallization tank is equipped with a discharge port, and the bottom cross-section of the crystallization tank is a smooth arc-shaped structure for discharging the concentrated crystal slurry. After the high-salt wastewater raw liquid has completed crystallization, it is first collected by the bottom structure, and finally the crystal slurry is discharged outward through the discharge port.

[0018] Furthermore, an expansion pipe is provided at the bottom of the central tube. The expansion of the expansion pipe is used for the rapid accumulation and upward discharge of gas bubbles in the raw liquid in the crystallizer. Specifically, the expansion structure of the expansion pipe creates a velocity reduction zone at the outlet of the expansion pipe during the upward process of the raw liquid. This is conducive to the rapid accumulation of gas bubbles entrained in the raw liquid and their upward discharge along the central tube to the gas-liquid separation space at the top of the evaporator, reducing the uneven local scouring caused by the adhesion and rupture of gas bubbles on the surface of the heat exchange tube.

[0019] The present invention has the following beneficial effects:

[0020] 1. This invention places the high-salt wastewater raw liquid in the external space of a rotating U-shaped tube bundle, a near-center ring tube, and a lower rotating ring tube, while the heat transfer medium flows inside the tube bundle. This allows the temperature gradient and salt concentration gradient of the raw liquid to be distributed gently over a large space, avoiding the formation of a strong supersaturation zone at the heat exchange wall surface in traditional structures, and fundamentally inhibiting heterogeneous nucleation of scale on the heat exchange surface. At the same time, by setting two switchable modes of reverse heat transfer under top steam inlet and forward heat transfer under bottom steam inlet, the flow direction of the heat transfer medium can be flexibly adjusted according to the change of raw liquid concentration. In the early stage of evaporation, reverse heat transfer is used to enhance efficiency, and in the later stage of evaporation, forward heat transfer is used to avoid local supercooling and crystallization, thereby achieving long-term cleaning of the heat exchange surface across the entire concentration range.

[0021] 2. The present invention also includes a rotating lifting assembly consisting of a main shaft, a connecting ring column, a rotating ring, a rotating column, and a stirring rod inside the evaporator and crystallizer. This assembly allows the lower rotating ring tube to rotate continuously during heat exchange, applying micro-disturbance to the raw liquid outside the tube and disrupting the stable adhesion of the solid-liquid boundary layer. Simultaneously, the stirring rod provides low-speed stirring to the crystal slurry at the bottom of the crystallizer, preventing crystal deposition and secondary scaling. Furthermore, the outward expansion tube at the bottom of the central tube accelerates the accumulation and upward displacement of bubbles in the raw liquid, reducing bubble adhesion on the surface of the heat exchange tube. The tangential connection structure of the main distribution tube and the diversion heating effect of the distribution branch tubes further maintain the temperature and concentration uniformity within the crystallizer, comprehensively improving the anti-scaling performance and operational stability of the equipment. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 This is a cross-sectional view of the internal structure of the present invention;

[0024] Figure 3 This is a front sectional view of the present invention;

[0025] Figure 4 This is a structural diagram of the rotary lifting assembly of the present invention;

[0026] Figure 5 This is a schematic diagram of the installation structure of the upper heat exchanger tube bundle of the present invention;

[0027] Figure 6 This is a top view of the mounting structure of the upper heat exchanger tube bundle of the present invention;

[0028] Figure 7 This is a cross-sectional view of the main structure of the present invention.

[0029] The attached diagram shows the following components and their corresponding names: 1. Crystallizer; 2. Evaporator; 3. Steam compressor; 4. Inlet pipe; 5. Main distribution pipe; 6. Raw material inlet pump; 7. Secondary steam outlet pipe; 8. Steam inlet pipe; 9. Distribution branch pipe; 10. Main shaft; 11. Discharge port; 12. Rotary U-shaped tube; 13. Steam return pipe; 14. Central through pipe; 15. Connecting ring column; 16. Rotating column; 17. Lower rotating ring column; 18. Proximal ring pipe; 19. Steam supply pipe; 20. Steam return pipe; 21. Rotating ring; 22. Stirring rod; 23. Outer expansion pipe. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the following description is provided in conjunction with embodiments and appendices. Figure 1-7 The present invention will be further described in detail below. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0031] Example 1: The present invention proposes a high-salt wastewater evaporation crystallization heat exchange anti-scaling treatment device, including a combined tank for high-salt wastewater evaporation crystallization and a parallel heat exchange tube bundle assembly for adjusting the evaporation crystallization heat exchange surface. The combined tank includes a crystallization tank 1 and an evaporation tank 2 stacked on each other.

[0032] Evaporator 2 is vertically inserted into the upper middle part of crystallizer 1 and connected to the bottom of crystallizer 1 with a central pipe 14 extending to the bottom of crystallizer 1. Crystallizer 1 is connected to the upper side of liquid inlet pipe 4. Liquid inlet pipe 4 is equipped with a raw liquid pump 6 for pumping in high-salt wastewater raw liquid. When high-salt wastewater raw liquid enters crystallizer 1 through raw liquid pump 6 and liquid inlet pipe 4, it is filled and the liquid level is maintained in the upper part of evaporator 2. During the continuous heat exchange process, water evaporates on its liquid surface.

[0033] The parallel heat exchanger tube bundle assembly includes a rotary U-shaped tube 12 and a near-center ring tube 18, as well as a lower rotary ring tube 17, which are vertically connected in the crystallizer 1 and the evaporator 2. The parallel heat exchanger tube bundle assembly is provided with a top steam inlet state and a bottom steam inlet state.

[0034] Specifically, under the top steam inlet state, the heat transfer medium achieves reverse heat transfer of the high-salt wastewater solution in evaporator 2 along the flow direction of the rotary U-shaped tube 12, the near-center ring tube 18, and the lower rotary ring tube 17. Under the bottom steam inlet state, the heat transfer medium achieves forward heat transfer of the high-salt wastewater solution in evaporator 2 along the flow direction of the near-center ring tube 18, the lower rotary ring tube 17, and the rotary U-shaped tube 12. "Reverse heat transfer" means that during the entry of the raw liquid, the entry direction of the high-salt wastewater raw liquid is from bottom to top. When the flow direction of the heat transfer medium is opposite to this, it is called reverse.

[0035] Similarly, when the flow direction of the heat transfer medium is the same as that of the heat transfer medium, it is considered to be positive. In this positive and negative heat transfer process, the high-salt wastewater raw liquid achieves "external flow" mode, while the steam, as the heat transfer medium, exhibits "internal flow" mode. The salt concentration gradient and temperature gradient of the raw liquid in the open space are distributed gently over a large range, making it difficult to form a strong supersaturated zone outside the tube wall of the parallel heat exchange tube bundle assembly. This fundamentally inhibits heterogeneous nucleation, that is, it inhibits the formation of scale on the heat exchange surface.

[0036] A steam compressor 3 is installed on one side of the crystallizer 1. The steam outlet of the steam compressor 3 is connected to a steam inlet pipe 8 that is connected to the bottom of the side of the evaporator 2. A steam delivery pipe 19 and a steam return pipe 20 are inserted into the steam inlet pipe 8.

[0037] The upper end of the evaporator 2 is connected to a secondary steam outlet pipe 7 that is connected to the return steam pipe 20, and the middle part of the evaporator 2 is provided with a main shaft 10 driven by a drive motor. The main shaft 10 extends into the interior of the evaporator 2 and the crystallizer 1 and is provided with a rotating lifting assembly.

[0038] The rotary lifting assembly includes a connecting ring column 15 that is connected to the top of the proximal ring tube 18. The lower end of the connecting ring column 15 is rotatably connected to a rotating column 16 via a rotating ring 21. The lower end of the rotating column 16 is connected to the lower rotating ring tube 17. The main shaft 10 extends through the rotating column 16 to the lower end where an agitator 22 is installed.

[0039] The bottom of the crystallization tank 1 is provided with a discharge port 11, and the bottom cross section of the crystallization tank 1 is an arc-shaped smooth structure for discharging the concentrated crystal slurry. After the high-salt wastewater raw liquid has completed crystallization, it is first collected by the bottom structure, and finally the crystal slurry is discharged outward through the discharge port 11.

[0040] In the actual evaporation and crystallization process, the specific heat exchange and anti-scaling operation flow is as follows:

[0041] When the equipment is in the top steam inlet state, the heat transfer medium, i.e., live steam or secondary steam compressed by the steam compressor 3, is first sent into the steam circuit pipe 13 through the steam delivery pipe 19, and then enters the rotary U-shaped tube 12. The heat transfer medium flows from bottom to top along the rotary U-shaped tube 12, and then sequentially enters the near-center ring pipe 18 and the lower rotary ring pipe 17, and finally returns to the steam compressor 3 through the return steam pipe 20.

[0042] During this process, the high-salt wastewater raw liquid is sent into the crystallization tank 1 through the raw liquid inlet pump 6 and the inlet pipe 4. The liquid level is maintained in the upper part of the evaporation tank 2. The raw liquid rises slowly from bottom to top in the evaporation tank 2 and forms counter-current convection heat exchange with the heat transfer medium on the outer walls of the rotating U-shaped tube 12, the near-center ring tube 18 and the lower rotating ring tube 17. Since the raw liquid always flows in the open space outside the tubes, while the heat transfer medium flows in the closed space inside the tubes, the temperature gradient and salt concentration gradient on the outer wall of the tubes are both gently distributed, making it difficult to form a local supersaturated zone, thereby effectively inhibiting the heterogeneous nucleation of scale on the outer wall of the heat exchange tubes.

[0043] When the equipment is in the bottom steam inlet state, the heat transfer medium first enters the near-center ring pipe 18, then flows downward through the lower rotating ring pipe 17, then enters the rotary U-shaped tube 12, and finally returns to the steam compressor 3 through the steam return pipe 13 and the return steam pipe 20. At this time, the overall flow direction of the heat transfer medium is the same as the flow direction of the raw liquid from bottom to top, forming positive heat transfer. In the positive heat transfer mode, the raw liquid undergoes a transition from a low temperature zone to a high temperature zone during its ascent, which helps to avoid local supercooling and crystallization, and is especially suitable for the later evaporation stage of high-concentration brine.

[0044] Under the two steam inlet conditions described above, the drive motor rotates the main shaft 10, which in turn drives the connecting ring column 15, rotating column 16, and lower rotating ring tube 17 to rotate synchronously via the rotating ring 21. Simultaneously, the stirring rod 22 at the lower end of the main shaft 10 continuously rotates at the bottom of the crystallizer 1, providing low-speed stirring to prevent crystal deposition at the bottom and promote smooth discharge of the crystal slurry from the discharge port 11. During rotation, the outer expansion tube 23 at the bottom of the central tube 14 accelerates the accumulation and upward discharge of rising bubbles in the raw liquid, reducing bubble adhesion on the surface of the heat exchange tube bundle and further enhancing the anti-scaling effect.

[0045] Example 2: Based on Example 1, the rotary U-shaped tube 12 is a heat transfer tube bundle structure with the ends connected and encircling in a circle. The lower end of the outer side of the rotary U-shaped tube 12 is fitted with a steam circuit pipe 13 that is connected to the steam supply pipe 19 and the return steam pipe 20. The lower rotary ring tube 17 is a columnar heat transfer tube bundle structure arranged in a ring. The diameter of the ring formed by the lower rotary ring tube 17 is the same as the diameter of the evaporator 2. Under the stirring action of the continuously rotating lower rotary ring tube 17, the part of the original liquid that has been heat transferred by the lower rotary ring tube 17 is rapidly disturbed from the crystallizer 1 to the evaporator 2, which further improves the heat transfer efficiency and avoids the occurrence of heat exchange dead zones.

[0046] The lower end of the steam compressor 3 is provided with a main distribution pipe 5. The distribution end of the main distribution pipe 5 is tangentially connected to the liquid inlet pipe 4. A distribution branch pipe 9 is provided on the distribution branch of the main distribution pipe 5. The distribution branch pipe 9 can divert part of the steam to the bottom of the crystallizer 1 to assist in heating the bottom crystal slurry and maintain the uniformity of the temperature field inside the crystallizer 1.

[0047] The bottom of the central pipe 14 is provided with an outer expansion pipe 23. The outer expansion of the outer expansion pipe 23 is used for the rapid accumulation and upward discharge of the gas bubbles in the raw liquid in the crystallizer 1. Specifically, the outer expansion structure of the outer expansion pipe 23 creates a velocity reduction zone at the outlet of the outer expansion pipe 23 during the upward process of the raw liquid. This is conducive to the rapid accumulation of gas bubbles entrained in the raw liquid and their upward discharge along the central pipe 14 to the gas-liquid separation space at the top of the evaporator 2, thereby reducing the uneven local scouring caused by the adhesion and rupture of gas bubbles on the surface of the heat exchange tube.

[0048] Example 3: This example combines the technical content of Example 1 and Example 2 to form the following usage method:

[0049] First, start the raw liquid inlet pump 6 to send the high-salt wastewater raw liquid tangentially into the crystallization tank 1 through the inlet pipe 4. After the raw liquid fills the crystallization tank 1, the liquid level rises to the upper middle part of the evaporation tank 2. Then, start the steam compressor 3 and select either the top steam inlet state or the bottom steam inlet state according to the initial concentration of the raw liquid: for raw liquid with a low initial concentration, the top steam inlet state is preferred, so that the heat transfer medium flows counterclockwise along the rotary U-shaped tube 12, the near-center ring tube 18, and the lower rotary ring tube 17, and the evaporation efficiency is enhanced by using counterclockwise heat transfer. As evaporation proceeds and the concentration of the raw liquid increases, the bottom steam inlet state can be switched to, so that the heat transfer medium flows forward along the near-center ring tube 18, the lower rotary ring tube 17, and the rotary U-shaped tube 12, to avoid excessively rapid cooling and crystallization in the high concentration area.

[0050] During the evaporation process, the drive motor drives the main shaft 10 to rotate, which in turn drives the lower rotating ring tube 17 and the stirring rod 22 to rotate continuously, maintaining the micro-disturbance state of the original liquid outside the tube and disrupting the boundary layer stability. The concentrated crystal slurry is continuously or intermittently discharged from the discharge port 11 at the bottom of the crystallizer 1 by the stirring rod 22. The main distribution pipe 5 supplements a small amount of steam to the bottom of the crystallizer 1 through the distribution branch pipe 9 to maintain the bottom temperature and prevent secondary scaling after the crystal slurry cools down.

[0051] The solution achieves the following results: through a reverse heat exchange structure where the raw liquid flows outside the pipe and the steam flows inside, combined with two switchable modes of top steam inlet and bottom steam inlet, as well as the mechanical disturbance and bubble guiding effect of the rotating lifting component, active scale prevention is achieved on the heat exchange surface throughout the evaporation and crystallization process.

[0052] In summary, this invention places the high-salt wastewater raw liquid in the space outside the tubes of the rotating U-shaped tube bundle, the near-center ring tube, and the lower rotating ring tube, while the heat transfer medium flows inside the tube bundle. This makes the temperature gradient and salt concentration gradient of the raw liquid gradually distributed over a large space, avoiding the formation of a strong supersaturation zone at the heat exchange wall in traditional structures, and fundamentally inhibiting the heterogeneous nucleation of scale on the heat exchange surface.

[0053] Meanwhile, by setting two switchable modes, reverse heat transfer in the top steam inlet state and forward heat transfer in the bottom steam inlet state, the flow direction of the heat transfer medium can be flexibly adjusted according to the change of the raw liquid concentration. In the early stage of evaporation, reverse heat transfer is used to enhance efficiency, and in the later stage of evaporation, forward heat transfer is used to avoid local overcooling and crystallization, thereby achieving long-term cleanliness of the heat exchange surface across the entire concentration range.

[0054] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-salinity wastewater evaporation crystallization heat exchange and anti-scaling treatment device, comprising a combined tank for high-salinity wastewater evaporation crystallization and a parallel heat exchange tube bundle assembly for adjusting the evaporation crystallization heat exchange surface, characterized in that, The combined tank includes a crystallizing tank (1) and an evaporating tank (2) stacked on top of each other. The evaporating tank (2) is vertically inserted into the upper middle part of the crystallizing tank (1) and has a central pipe (14) extending to the bottom of the crystallizing tank (1) at its bottom. The parallel heat exchange tube bundle assembly includes a rotating U-shaped tube (12) and a near-center ring tube (18) vertically connected in the crystallizing tank (1) and the evaporating tank (2) as well as a lower rotating ring tube (17). The parallel heat exchange tube bundle assembly is provided with a top steam inlet state and a bottom steam inlet state. In the top steam inlet state, the heat transfer medium flows along the flow direction of the rotary U-shaped tube (12), the near-center ring tube (18) and the lower rotary ring tube (17) to achieve reverse heat transfer of the high-salt wastewater solution in the evaporator (2). In the bottom steam inlet state, the heat transfer medium flows along the flow direction of the near-center ring tube (18), the lower rotary ring tube (17) and the rotary U-shaped tube (12) to achieve forward heat transfer of the high-salt wastewater solution in the evaporator (2).

2. The high-salt wastewater evaporation crystallization heat exchange and anti-scaling treatment equipment according to claim 1, characterized in that, A steam compressor (3) is provided on one side of the crystallizer (1). The steam outlet of the steam compressor (3) is connected to a steam inlet pipe (8) that is connected to the bottom of the side of the evaporator (2). A steam delivery pipe (19) and a steam return pipe (20) are inserted into the steam inlet pipe (8).

3. The high-salt wastewater evaporation crystallization heat exchange and anti-scaling treatment equipment according to claim 2, characterized in that, The upper end of the evaporator (2) is connected to a secondary steam outlet pipe (7) that is connected to the return steam pipe (20), and the middle part of the evaporator (2) is provided with a main shaft (10) driven by a motor. The main shaft (10) extends into the interior of the evaporator (2) and the crystallizer (1) and is provided with a rotating lifting assembly.

4. The high-salt wastewater evaporation crystallization heat exchange and anti-scaling treatment equipment according to claim 3, characterized in that, The rotary lifting assembly includes a connecting ring column (15) that is connected to the top of the proximal ring tube (18). The lower end of the connecting ring column (15) is rotatably connected to a rotating column (16) via a rotating ring (21). The lower end of the rotating column (16) is connected to the lower rotating ring tube (17). The main shaft (10) extends through the rotating column (16) to the lower end where an agitator (22) is installed.

5. The high-salt wastewater evaporation crystallization heat exchange and anti-scaling treatment equipment according to claim 4, characterized in that, The rotating U-shaped tube (12) is a heat transfer tube bundle structure that is connected end to end and arranged in a circle. The lower end of the outer side of the rotating U-shaped tube (12) is fitted with a steam circuit pipe (13) that is connected to the steam supply pipe (19) and the steam return pipe (20). The lower rotating ring tube (17) is a columnar heat transfer tube bundle structure arranged in a ring. The diameter of the ring formed by the lower rotating ring tube (17) is the same as the diameter of the evaporator (2).

6. The high-salt wastewater evaporation crystallization heat exchange and anti-scaling treatment equipment according to claim 2, characterized in that, The upper side of the crystallizer (1) is connected to the liquid inlet pipe (4), and the delivery end of the liquid inlet pipe (4) is equipped with a raw liquid inlet pump (6) for pumping in the raw liquid of high-salt wastewater.

7. The high-salinity wastewater evaporation crystallization heat exchange and anti-scaling treatment equipment according to claim 6, characterized in that, The lower end of the steam compressor (3) is provided with a main distribution pipe (5), the distribution end of the main distribution pipe (5) is tangentially connected to the liquid inlet pipe (4), and a distribution branch pipe (9) is provided on the distribution branch of the main distribution pipe (5).

8. The high-salinity wastewater evaporation crystallization heat exchange and anti-scaling treatment equipment according to claim 1, characterized in that, The bottom of the crystallization tank (1) is provided with a discharge port (11), and the bottom cross section of the crystallization tank (1) is an arc-shaped smooth structure for discharging the concentrated crystal slurry.

9. The high-salinity wastewater evaporation crystallization heat exchange and anti-scaling treatment equipment according to claim 1, characterized in that, The bottom of the central tube (14) is provided with an outer expansion tube (23), which is used for the rapid accumulation and upward discharge of the original liquid bubbles in the crystallizer (1).

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