Forced circulation evaporating crystallizer with refrigerating circuit

Abstract

The invention relates to the technical field of wastewater treatment equipment, in particular to a forced circulation evaporation crystallizer with a refrigeration loop, which comprises a circulation pipe, a preheating chamber, a stock solution pipe, an input outer pipe, an output outer pipe, a compression pipe, a crystallization pipe, a liquid distributor, a flow combiner, a heat exchange outer pipe and a transition pipe, through the superposition design of the heat exchange outer pipe and the heat exchange inner pipe, the heat obtained by the high-salinity wastewater in the single circulation process is greatly increased, the evaporation efficiency of the high-salinity wastewater in the single circulation process is improved, the circulation times required by the treatment of the high-salinity wastewater in unit volume are reduced, and the energy consumption is reduced. Therefore, the use energy consumption of the forced circulation evaporation crystallizer is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment equipment, in particular to a forced circulation evaporation crystallizer with a refrigeration circuit. Background Art

[0002] In the prior art, evaporation and concentration desalination is the most economical and effective method for desalination of high-salt wastewater, and various evaporation and concentration technologies for high-salt wastewater, such as multi-effect evaporation, multi-stage flash evaporation, and steam compression condensation, have been gradually developed in the process of applying different wastewater treatment scenarios at different development stages. In the process of applying the above-mentioned evaporation and desalination process to treat high-salt wastewater, as the desalination work continues, the salt-containing components therein are getting closer and closer to the upper limit of their saturation in the wastewater, that is, the salt concentration of the high-salt wastewater in the evaporator is also gradually increasing, and in the process of its salt concentration increasing, the obtained high-salt wastewater concentrate will gradually become more viscous.

[0003] At this time, the natural circulation speed of the solution generated only by the density difference between the evaporation chamber and the solution in the circulation tube will gradually decrease under the friction resistance between the increasingly viscous concentrated solution and the tube wall; if high-concentration high-salt wastewater precipitates crystallized salt, due to the decrease in circulation speed, the possibility of the precipitated crystallized salt adhering to the inner wall of the evaporation crystallizer to form scale will also increase, thereby reducing the treatment efficiency of the evaporation crystallizer for high-salt wastewater. Therefore, a circulation pump is usually introduced into the evaporation desalination process, so that the high-salt wastewater in the evaporation crystallizer is changed from natural circulation to forced circulation under the action of the circulation pump, so that the high-salt wastewater maintains a relatively stable circulation speed during the treatment process.

[0004] In actual production, workers usually increase the output power of the circulation pump and adjust the circulation speed to a higher level to prevent crystals from precipitating and scaling on the inner wall after the concentration of high-salt wastewater increases. However, as the circulation speed increases, the single circulation time of unit volume of high-salt wastewater in the evaporation chamber will also be shortened. The heat exchange time between high-salt wastewater and high-temperature steam in the evaporation chamber is short, which is bound to reduce the heating efficiency of high-salt wastewater in a single cycle. The reduction in heating efficiency is bound to result in a unit volume of high-salt wastewater having to undergo multiple cycles of evaporation to obtain a concentrated liquid that meets the standards, greatly increasing the working energy consumption of the evaporator crystallizer.

[0005] In view of this, in order to overcome the above technical problems, the present invention proposes a forced circulation evaporation crystallizer with a refrigeration circuit. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art, the technical solution adopted by the present invention to solve the technical problem is: a forced circulation evaporation crystallizer with a refrigeration circuit described in the present invention comprises:

[0007] An evaporation concentrator, wherein a circulation pipe is connected through the top of the evaporation concentrator;

[0008] A circulation pump, wherein the circulation pump is connected to the bottom end of the evaporation concentrator through a circulation pipe;

[0009] It is characterized by further comprising:

[0010] A preheating chamber, wherein the top and bottom of the preheating chamber are both connected to the circulation pipe; a raw liquid pipe is horizontally penetrated through the side wall of the preheating chamber;

[0011] An evaporation chamber, wherein the evaporation chamber is located inside the evaporation concentrator, an input outer tube is penetrated through the upper side wall of the evaporation chamber, and an output outer tube is penetrated through the lower side wall of the evaporation chamber;

[0012] The concentration chamber is located below the evaporation chamber, and the side wall of the concentration chamber is penetrated and connected with a compression tube, a circulation tube and a crystallization tube in sequence from top to bottom.

[0013] Preferably, the evaporation chamber comprises:

[0014] A liquid distributor, which is located at the upper end of the evaporation chamber and has multiple circles of liquid distribution holes evenly arranged from the inside to the outside;

[0015] A combiner, which is located at the lower end of the evaporation chamber and has evenly arranged combining holes at the same position as the liquid distributor;

[0016] The heat exchange outer tube is a spiral twisted tube with an elliptical cross-section. The heat exchange outer tube is located between the liquid distributor and the combiner, and the heat exchange outer tube is connected to the liquid distribution hole and the combiner hole.

[0017] Preferably, the vertical cross-section of the liquid distributor is a "convex"-shaped structure, and the horizontal length of the raised portion at the top is greater than the inner diameter of the circulation pipe.

[0018] Preferably, the liquid distribution holes and the confluence holes are both cylindrical through holes; the heat exchange outer tube is connected to the liquid distributor and the confluence hole through a transition tube, one end of the transition tube is circular and the other end is elliptical; the circular end of the transition tube is fixedly connected to the liquid distributor and the confluence hole, and is communicated with the liquid distribution holes and the confluence hole; the elliptical end of the transition tube is fixedly connected to the end of the heat exchange outer tube.

[0019] Preferably, the interior of the liquid distributor is a hollow chamber, and one end of the liquid distributor is penetrated and connected with an input inner tube.

[0020] Preferably, the heat exchange outer tube is sheathed with a heat exchange inner tube of the same structure and smaller size; the heat exchange inner tube is connected with the heat conductive tube extending into the liquid distribution hole and the confluence hole through a transition tube; the heat conductive tube is connected with the hollow chamber inside the liquid distributor through a connecting tube.

[0021] Preferably, the combiner has an annular cavity structure, and the inner ring diameter of the annular cavity structure is smaller than the farthest distance between the inner ring heat exchange outer tubes; the heat conductive tube extending into the combining hole is connected to the annular cavity inside the combiner through a connecting pipe, and the side wall at one end of the annular cavity is connected and penetrated by an output inner tube.

[0022] Preferably, the inner wall of the outer heat exchange tube and the outer wall of the inner heat exchange tube are both subjected to pre-film anti-scaling treatment, and the outer heat exchange tube, the inner heat exchange tube and the transition tube are detachably connected.

[0023] Preferably, the output inner tube and the output outer tube both extend into the upper side wall of the preheating chamber, are wound in a double helix in the preheating chamber, and merge into a collecting tube extending out of the preheating chamber at the bottom of the preheating chamber.

[0024] Preferably, a condensation loop is provided in the heat exchange chamber, and the upper and lower ends of the condensation loop both extend out of the heat exchange chamber and are connected to a refrigeration circuit.

[0025] The beneficial effects of the present invention are as follows:

[0026] 1. Through the superposition design of the outer heat exchange tube and the inner heat exchange tube, the heat obtained by the high-salt wastewater in a single cycle is greatly increased, the evaporation efficiency of the high-salt wastewater in a single cycle is improved, and the number of cycles required for the treatment of unit volume of high-salt wastewater is reduced, thereby reducing the energy consumption of the forced circulation evaporation crystallizer.

[0027] 2. After the high-temperature steam in the output inner tube and the output outer tube, the high-temperature refrigerant in the condensing loop tube in the heat exchange chamber and the high-salt wastewater in the preheating chamber are fully preheated, the high-temperature steam in the output inner tube and the output outer tube converges into the collecting tube and flows out of the preheating chamber with the collecting tube to be condensed into distilled water for storage; the high-temperature refrigerant in the condensing loop tube is also cooled and refluxed to the expansion valve of the refrigeration circuit for refrigeration operation, thereby realizing the full utilization of waste heat and further reducing the energy consumption of the forced circulation evaporator crystallizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below in conjunction with the accompanying drawings.

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 It is a three-dimensional structural schematic diagram of the evaporation concentrator of the present invention;

[0031] Figure 3 is a sectional view of the overall structure of the evaporation chamber of the present invention;

[0032] Figure 4 is a schematic diagram of the three-dimensional structure of the liquid distributor of the present invention;

[0033] Figure 5 The present invention Figure 3 The enlarged view of point A in the middle;

[0034] Figure 6 It is a three-dimensional structural cross-sectional view of the heat exchange outer tube and the heat exchange inner tube of the present invention;

[0035] Figure 7 It is a structural schematic diagram of the preheating chamber of the present invention.

[0036] In the figure: 1. evaporation concentrator; 2. circulation pipe; 3. circulation pump; 4. preheating chamber; 5. raw liquid pipe; 6. evaporation chamber; 7. input outer pipe; 8. output outer pipe; 9. concentration chamber; 10. compression pipe; 11. crystallization tube; 12. liquid distributor; 13. liquid distribution hole; 14. combiner; 15. combining hole; 16. heat exchange outer pipe; 17. transition pipe; 18. input inner pipe; 19. heat exchange inner pipe; 20. heat transfer tube; 21. connecting pipe; 22. output inner pipe; 23. collecting pipe; 24. condensation ring pipe. DETAILED DESCRIPTION

[0037] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention will be further explained below in conjunction with the accompanying drawings and specific implementation methods.

[0038] like Figures 1 to 7 As shown, an embodiment of the present invention provides a forced circulation evaporation crystallizer with a refrigeration circuit, comprising:

[0039] An evaporation concentrator 1, wherein a circulation pipe 2 is connected through the top of the evaporation concentrator 1;

[0040] A circulation pump 3, wherein the circulation pump 3 is connected to the bottom end of the evaporation concentrator 1 through a circulation pipe 2;

[0041] Also includes:

[0042] A preheating chamber 4, wherein the top and bottom of the preheating chamber 4 are both connected to the circulation pipe 2; a raw liquid pipe 5 is horizontally penetrated through the side wall of the preheating chamber 4;

[0043] An evaporation chamber 6, wherein the evaporation chamber 6 is located inside the evaporation concentrator 1, an upper side wall of the evaporation chamber 6 is penetrated and connected with an input outer tube 7, and a lower side wall of the evaporation chamber 6 is penetrated and connected with an output outer tube 8;

[0044] A concentration chamber 9, wherein the concentration chamber 9 is located below the evaporation chamber 6, and the side wall of the concentration chamber 9 is penetrated and connected with a compression tube 10, a circulation tube 2 and a crystallization tube 11 in sequence from top to bottom;

[0045] As an embodiment of the present invention, the evaporation chamber 6 comprises:

[0046] A liquid distributor 12, the liquid distributor 12 is located at the upper end of the evaporation chamber 6 and is provided with multiple circles of liquid distribution holes 13 evenly arranged from the inside to the outside;

[0047] The combiner 14 is located at the lower end of the evaporation chamber 6 and has evenly arranged combining holes 15 at the same position as the liquid distributor 12;

[0048] The heat exchange outer tube 16 is a spirally twisted tube with an elliptical cross section. The heat exchange outer tube 16 is located between the liquid distributor 12 and the combiner 14 , and the heat exchange outer tube 16 is connected to the liquid distribution hole 13 and the combiner hole 15 .

[0049] As an embodiment of the present invention, the vertical cross-section of the liquid distributor 12 is a “convex”-shaped structure, and the horizontal length of the raised portion at the top is greater than the inner diameter of the circulation pipe 2 .

[0050] In the process of desalting high-salt wastewater through evaporation and concentration process, first, open the switch valve of the input outer pipe 7 on the upper side wall of the evaporation chamber 6 to allow the raw steam to enter the evaporation chamber 6 along the input outer pipe 7. After ensuring that the heating of the evaporation chamber 6 is normal, the high-salt wastewater to be treated is introduced into the preheating chamber 4 through the raw liquid pipe 5. After being fully preheated in the preheating chamber 4, the high-salt wastewater flows from bottom to top through the circulation pipe 2 under the action of the circulation pump 3 and enters the interior of the evaporation concentrator 1 from the top. The portion of the circulation pipe 2 extending from the top into the interior of the evaporation concentrator 1 gradually narrows from top to bottom, and the horizontal length of the raised portion at the top of the liquid distributor 12 of the evaporation chamber 6 is greater than the inner diameter of the circulation pipe 2, so that when the high-salinity wastewater flows through the circulation pipe 2 at the top of the evaporation concentrator 1, the flow rate is increased at the narrowed portion of the inner diameter, and collides and disperses with the raised portion at the top of the liquid distributor 12, thereby more quickly and effectively dispersing the high-salinity wastewater entering the evaporation concentrator 1 to the surface of the liquid distributor 12, so that the high-salinity wastewater quickly and evenly enters the liquid distribution hole 13, and enters the heat exchange outer tube 16 through the liquid distribution hole 13 for heating and evaporation;

[0051] The high-salt wastewater entering the heat exchange outer tube 16 exchanges heat with the raw steam entering the evaporation chamber 6 through the input outer tube 7, thereby realizing heating and evaporation of the high-salt wastewater; in order to improve the heating efficiency of high-salt wastewater by high-temperature steam under forced circulation, the heat exchange outer tube 16 of the present invention is a spiral twisted tube with an elliptical cross-sectional shape. When the high-salt wastewater flows in the heat exchange outer tube 16 of this structure, it will spiral downward close to the inner wall of the heat exchange outer tube 16 under the action of centrifugal force, thereby increasing the surface area of ​​the heat exchange outer tube 16, increasing the contact area between the high-salt wastewater and the inner wall of the heat exchange outer tube 16, and increasing the flow distance of the high-salt wastewater in the heat exchange outer tube 16, thereby extending the heat exchange time of the high-salt wastewater by the high-temperature steam through the heat exchange outer tube 16; after the high-salt wastewater is fully heated in the process of passing through the heat exchange outer tube 16, it flows through the confluence hole 15 of the combiner 14 and falls into the concentration chamber 9 below the evaporation chamber 6. The steam part which is vaporized by high temperature flows out along the compression pipe 10 above the concentration chamber 9, and after filtering the liquid water droplets entrained inside, it is processed by the compressor and then re-injected into the evaporation chamber 6 for auxiliary heating. The remaining high-salt wastewater concentrate is stored at the bottom of the condensation chamber, waiting for the concentration sensor arranged at the bottom of the condensation chamber to detect the salt concentration in the concentrate. If the target concentration has been reached, the control center opens the valve of the crystallization tube 11 and sends it into the crystallization chamber for cooling, crystallization and separation through the evaporation system of the refrigeration circuit; if the target concentration has not been reached, the control center opens the valve of the circulation pipe 2 at the bottom and sends it back to the preheating chamber 4 for secondary treatment through the action of the circulation pump 3.

[0052] As an embodiment of the present invention, the liquid distribution hole 13 and the confluence hole 15 are both cylindrical through holes; the heat exchange outer tube 16 is connected to the liquid distributor 12 and the confluence hole 14 through a transition tube 17, one end of the transition tube 17 is circular and the other end is elliptical; the circular end of the transition tube 17 is fixedly connected to the liquid distributor 12 and the confluence hole 14, and is connected to the liquid distribution hole 13 and the confluence hole 15; the elliptical end of the transition tube 17 is fixedly connected to the end of the heat exchange outer tube 16.

[0053] During operation, the liquid distribution hole 13 of the liquid distributor 12 and the confluence hole 15 of the confluence device 14 are both cylindrical through holes that are easy to process, thereby reducing the processing difficulty of the present invention; the heat exchange outer tube 16 is connected to the liquid distributor 12 and the confluence device 14 through a transition tube 17 with a circular end and an elliptical end at the other end, and the main components of the evaporation chamber 6 are processed separately, which not only reduces the processing difficulty but also makes it easy to increase the processing scale.

[0054] As an embodiment of the present invention, the interior of the liquid distributor 12 is a hollow chamber, and one end of the liquid distributor 12 is penetrated and connected with an input inner tube 18 .

[0055] As an embodiment of the present invention, the heat exchange outer tube 16 is provided with a heat exchange inner tube 19 of the same structure and smaller size; the heat exchange inner tube 19 is connected to the heat conductive tube 20 extending into the liquid distribution hole 13 and the confluence hole 15 through the transition tube 17; the heat conductive tube 20 is connected to the hollow chamber inside the liquid distributor 12 through the connecting tube 21.

[0056] As an embodiment of the present invention, the combiner 14 has an annular cavity structure, and the inner ring diameter of the annular cavity structure is smaller than the farthest distance between the inner ring heat exchange outer tubes 16; the heat conductive tube 20 extending into the combining hole 15 is connected to the annular cavity inside the combiner 14 through a connecting tube 21, and the side wall of one end of the annular cavity is connected and penetrated by an output inner tube 22.

[0057] During operation, the interior of the liquid distributor 12 is set as a hollow chamber, and a fixed input inner tube 18 is passed through one end of the liquid distributor 12 to introduce high-temperature steam processed by the compressor into the liquid distributor 12, so that the high-salt wastewater is in a heated state while entering the evaporation concentrator 1 and falling on the liquid distributor 12 for liquid distribution, thereby reducing the heating burden of the heat exchange outer tube 16; a heat exchange inner tube 19 with the same structure and smaller size is sleeved in the heat exchange outer tube 16, and the heat exchange inner tube 19 is connected to the internal chamber of the liquid distributor 12 through a transition tube 17, a heat conducting tube 20 and a connecting tube 21, so that the high-temperature steam introduced into the liquid distributor 12 through the input inner tube 18 flows into the heat exchange inner tube 19, so that the high-salt wastewater between the two tubes is heated synchronously by the high-temperature steam in the heat exchange inner tube 19 and the heat exchange outer tube 16, thereby The heating efficiency of the evaporation chamber 6 for the high-salt wastewater is improved; since the interior of the combiner 14 is a solid center and the remaining annular parts are hollow, the high-temperature steam in the heat exchange inner tube 19 completes the heating of the high-salt wastewater. When entering the combiner 14 through the connecting tube 21, the smaller cavity area inside the combiner 14 allows the high-temperature steam to leave the combiner 14 at a faster speed and flow out from the output inner tube 22, thereby avoiding the waste of heat carried by the high-temperature steam; through the superimposed design of the heat exchange outer tube 16 and the heat exchange inner tube 19, the heat obtained by the high-salt wastewater in a single cycle is greatly increased, the evaporation efficiency of the high-salt wastewater in a single cycle is improved, and the number of cycles required for the treatment of unit volume of high-salt wastewater is reduced, thereby reducing the energy consumption of the forced circulation evaporation crystallizer.

[0058] As an embodiment of the present invention, the inner wall of the outer heat exchange tube 16 and the outer wall of the inner heat exchange tube 19 are both pre-coated for anti-scaling, and the outer heat exchange tube 16 and the inner heat exchange tube 19 are detachably connected to the transition tube 17 .

[0059] During operation, since both the outer heat exchange tube 16 and the inner heat exchange tube 19 are spirally twisted tubes with elliptical cross-sections, their shape improves the heating efficiency of high-salt wastewater, but their special shape also makes them more prone to scaling than cylindrical tubes, and once scaled, they are inevitably difficult to clean; for this reason, the inner wall of the outer heat exchange tube 16 and the outer wall of the inner heat exchange tube 19 are pre-coated and anti-scaling treated before being put into use to avoid scaling during use; if scaling still occurs, the detachable connection between the outer heat exchange tube 16 and the inner heat exchange tube 19 and the transition tube 17, such as a threaded connection, allows maintenance personnel to remove the outer heat exchange tube 16 and the inner heat exchange tube 19 for cleaning or replacement separately, thereby reducing the adverse effects of scaling problems on the present invention.

[0060] As an embodiment of the present invention, the output inner tube 22 and the output outer tube 8 both extend into the upper side wall of the preheating chamber 4, and the output inner tube 22 and the output outer tube 8 are wound in a double helix in the preheating chamber 4, and converge into a collecting tube 23 extending out of the preheating chamber 4 at the bottom of the preheating chamber 4.

[0061] As an embodiment of the present invention, a condensation loop pipe 24 is provided in the heat exchange chamber, and the upper and lower ends of the condensation loop pipe 24 extend out of the heat exchange chamber and are connected to a refrigeration circuit.

[0062] During operation, the output inner tube 22 and the output outer tube 8 extending from the evaporation chamber 6 carry the high-temperature steam that has completed the heating task of the high-salt wastewater in the evaporation chamber 6 and flow into the preheating chamber 4, and the high-salt wastewater to be treated in the preheating chamber 4 is preheated through the output inner tube 22 and the output outer tube 8 that are double-helix-wound in the preheating chamber 4; after the high-temperature steam in the output inner tube 22 and the output outer tube 8, the high-temperature refrigerant in the condensation loop 24 in the heat exchange chamber, and the high-salt wastewater in the preheating chamber 4 are fully preheated, the high-temperature steam in the output inner tube 22 and the output outer tube 8 are merged into the collecting tube 23 and flow out of the preheating chamber 4 with the collecting tube 23 to condense into distilled water for storage; the high-temperature refrigerant in the condensation loop 24 is also cooled and refluxed to the expansion valve of the refrigeration circuit to perform refrigeration operations, thereby realizing the full utilization of the working waste heat of the relevant components in the evaporation and desalination process, and further reducing the energy consumption of the forced circulation evaporation crystallizer.

[0063] The above shows and describes the basic principles, main features and significant advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above specific embodiments. Without departing from the spirit and scope of the present invention, the present invention may also be modified and improved to adapt to different usage environments and customer needs. These modifications and improvements fall within the scope of protection of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A forced circulation evaporation crystallizer with a refrigeration circuit, comprising: An evaporation concentrator (1), wherein a circulation pipe (2) is connected through the top of the evaporation concentrator (1); A circulation pump (3), wherein the circulation pump (3) is connected to the bottom end of the evaporation concentrator (1) through a circulation pipe (2); It is characterized by further comprising: A preheating chamber (4), wherein the top and bottom ends of the preheating chamber (4) are both connected to the circulation pipe (2); a raw liquid pipe (5) is horizontally penetrated through the side wall of the preheating chamber (4); An evaporation chamber (6), the evaporation chamber (6) being located inside the evaporation concentrator (1), the upper side wall of the evaporation chamber (6) being connected to an input outer tube (7), and the lower side wall of the evaporation chamber (6) being connected to an output outer tube (8); A concentration chamber (9), wherein the concentration chamber (9) is located below the evaporation chamber (6), and a compression tube (10), a circulation tube (2) and a crystallization tube (11) are sequentially penetrated and connected through the side wall of the concentration chamber (9) from top to bottom.

2. A forced circulation evaporation crystallizer with a refrigeration circuit according to claim 1, characterized in that: The evaporation chamber (6) comprises: A liquid distributor (12), the liquid distributor (12) being located at the upper end of the evaporation chamber (6) and having a plurality of liquid distribution holes (13) evenly arranged from the inside to the outside; A combiner (14), the combiner (14) being located at the lower end of the evaporation chamber (6) and having evenly arranged combiner holes (15) at the same position as the liquid distributor (12); The heat exchange outer tube (16) is a spirally twisted tube with an elliptical cross-section. The heat exchange outer tube (16) is located between the liquid distributor (12) and the combiner (14), and the heat exchange outer tube (16) is connected to the liquid distribution hole (13) and the combiner hole (15).

3. A forced circulation evaporation crystallizer with a refrigeration circuit according to claim 2, characterized in that: The vertical cross-section of the liquid distributor (12) is a "convex"-shaped structure, and the horizontal length of the raised portion at the top is greater than the inner diameter of the circulation pipe (2).

4. A forced circulation evaporation crystallizer with a refrigeration circuit according to claim 3, characterized in that: The liquid distribution hole (13) and the confluence hole (15) are both cylindrical through holes; the heat exchange outer tube (16) is connected to the liquid distributor (12) and the confluence hole (14) via a transition tube (17); one end of the transition tube (17) is circular and the other end is elliptical; the circular end of the transition tube (17) is fixedly connected to the liquid distributor (12) and the confluence hole (14), and is in communication with the liquid distribution hole (13) and the confluence hole (15); the elliptical end of the transition tube (17) is fixedly connected to the end of the heat exchange outer tube (16).

5. A forced circulation evaporation crystallizer with a refrigeration circuit according to claim 4, characterized in that: The interior of the liquid distributor (12) is a hollow chamber, and one end of the liquid distributor (12) is penetrated and connected with an input inner tube (18).

6. A forced circulation evaporation crystallizer with a refrigeration circuit according to claim 5, characterized in that: The heat exchange outer tube (16) is sleeved with a heat exchange inner tube (19) of the same structure and smaller size; the heat exchange inner tube (19) is connected to a heat conduction tube (20) extending into the liquid distribution hole (13) and the confluence hole (15) through a transition tube (17); the heat conduction tube (20) is connected to a hollow chamber inside the liquid distributor (12) through a connecting tube (21).

7. A forced circulation evaporation crystallizer with a refrigeration circuit according to claim 6, characterized in that: The combiner (14) has an annular cavity structure inside, and the inner ring diameter of the annular cavity structure is smaller than the farthest distance between the inner ring heat exchange outer tubes (16); the heat conduction tube (20) extending into the combining hole (15) is connected to the annular cavity inside the combiner (14) through a connecting tube (21), and the side wall of one end of the annular cavity is connected and penetrated by an output inner tube (22).

8. The forced circulation evaporation crystallizer with a refrigeration circuit according to claim 6, characterized in that: The inner wall of the outer heat exchange tube (16) and the outer wall of the inner heat exchange tube (19) are both subjected to pre-film anti-scaling treatment, and the outer heat exchange tube (16) and the inner heat exchange tube (19) are detachably connected to the transition tube (17).

9. The forced circulation evaporation crystallizer with a refrigeration circuit according to claim 7, characterized in that: The output inner tube (22) and the output outer tube (8) both extend into the upper side wall of the preheating chamber (4), the output inner tube (22) and the output outer tube (8) are wound in a double helix in the preheating chamber (4), and converge into a collecting tube (23) extending out of the preheating chamber (4) at the bottom of the preheating chamber (4).

10. A forced circulation evaporation crystallizer with a refrigeration circuit according to claim 9, characterized in that: A condensation loop pipe (24) is provided in the heat exchange chamber, and the upper and lower ends of the condensation loop pipe (24) both extend out of the heat exchange chamber and are connected to a refrigeration circuit.

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