High-salt wastewater evaporation and crystallization treatment system and method

Abstract

The present invention relates to the field of wastewater treatment technology, and in particular to a high-salt wastewater evaporation and crystallization treatment system and method. The high-salt wastewater evaporation and crystallization treatment system comprises: a pretreatment module, an evaporation and crystallization module, a steam heat pump module, and an air circulation module. The evaporation and crystallization module comprises an evaporation and crystallization device and a heat exchanger. The steam heat pump module comprises a steam heat pump unit and a steam generator. The air circulation module comprises a steam-water separator. The heat exchanger is connected to the evaporation and crystallization device, and the heat exchanger is used to perform heat exchange with the high-salt wastewater in the evaporation and crystallization device. The liquid inlet of the evaporation and crystallization device is connected to the pretreatment module. The high-salt wastewater evaporation and crystallization treatment system and method provided by the present invention solve the defects of low thermal energy utilization and slow evaporation and crystallization efficiency in the high-salt wastewater treatment methods of the prior art, and improve the heat utilization efficiency and separation efficiency in the concentration and crystallization process of the high-salt wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and in particular to a system and method for evaporating and crystallizing high-salt wastewater. Background Art

[0002] Currently, high-salinity wastewater treatment methods both domestically and internationally include electrodialysis, membrane treatment, and evaporation. Evaporation is currently one of the primary methods for achieving zero emissions. Common evaporation processes with industry-wide applications include mechanical compression reevaporation (MVR), multiple-effect evaporation (MEC), and submerged combustion (SCE).

[0003] However, in the MVR or MEC process, there is still a certain amount of mother liquor that cannot be crystallized and solidified, and the treatment is incomplete. Subsequent disposal measures must be provided. In addition, high-salt wastewater with high organic matter concentration and high hardness has the problems of easy scaling and frequent cleaning. The operation stability of the submerged combustion process is better than that of MVR or MEC, and it can directly achieve crystallization and solidification of high-salt water, but it requires natural gas or biogas as the main energy source, and the investment and operating costs are very high, which cannot meet market demand. In addition, the negative pressure vacuum scraper evaporation crystallization device that has appeared in recent years is used for the treatment of high-salt wastewater. It can make the final product crystallize and solidify. The device has a low tendency to scale and is stable for a long time. However, it also has problems such as low thermal energy utilization, slow evaporation and crystallization efficiency, and high operating costs.

[0004] Therefore, there is an urgent need for a high-salt wastewater evaporation and crystallization treatment system and method to solve the above problems. Summary of the Invention

[0005] The present invention provides a high-salt wastewater evaporation and crystallization treatment system and method, which are used to solve the defects of low thermal energy utilization and slow evaporation and crystallization efficiency in the high-salt wastewater treatment method in the prior art, and improve the heat utilization efficiency and separation efficiency in the concentration and crystallization process of high-salt wastewater.

[0006] On one hand, the present invention provides a high-salt wastewater evaporation and crystallization treatment system, comprising: a pretreatment module, an evaporation and crystallization module, a steam heat pump module and an air circulation module, wherein the evaporation and crystallization module comprises an evaporation and crystallization device and a heat exchanger, the steam heat pump module comprises a steam heat pump unit and a steam generator, and the air circulation module comprises a steam-water separator;

[0007] The heat exchanger is connected to the evaporation crystallization device, and the heat exchanger is used to perform heat exchange with the high-salt wastewater in the evaporation crystallization device. The liquid inlet of the evaporation crystallization device is connected to the pretreatment module;

[0008] The air source side inlet of the steam heat pump unit is connected to the air outlet of the evaporation crystallization device, the air source side outlet of the steam heat pump unit is connected to the inlet of the steam-water separator, the gas phase outlet of the steam-water separator is connected to the air inlet of the evaporation crystallization device, the liquid outlet of the steam heat pump unit is connected to the liquid inlet of the steam generator, the steam outlet of the steam generator is connected to the steam inlet of the heat exchanger, and the liquid outlet of the steam generator is connected to the liquid inlet of the steam heat pump unit.

[0009] According to the high-salt wastewater evaporation and crystallization treatment system provided by the present invention, the condensed water outlet of the heat exchanger is connected to the liquid inlet of the steam heat pump unit.

[0010] According to the high-salt wastewater evaporation and crystallization treatment system provided by the present invention, the steam heat pump module also includes a pressure water tank, the first liquid inlet of the pressure water tank is connected to the liquid outlet of the steam generator, the second liquid inlet of the pressure water tank is connected to the condensed water outlet of the heat exchanger, and the liquid outlet of the pressure water tank is connected to the liquid inlet of the steam heat pump unit.

[0011] According to the high-salt wastewater evaporation and crystallization treatment system provided by the present invention, a driving pump is provided on the pipeline connecting the first liquid inlet of the pressure water tank and the liquid outlet of the steam generator.

[0012] According to the high-salt wastewater evaporation and crystallization treatment system provided by the present invention, the air circulation module also includes a circulation fan, which is arranged on a pipeline connecting the gas phase outlet of the steam-water separator and the air inlet of the evaporation and crystallization device.

[0013] The high-salt wastewater evaporation and crystallization treatment system provided by the present invention also includes an external drainage module, which includes a crystallization water production tank and an external drainage processor connected in sequence, and the liquid phase outlet of the steam-water separator is connected to the liquid inlet of the crystallization water production tank.

[0014] According to the high-salt wastewater evaporation crystallization treatment system provided by the present invention, the pretreatment module includes a raw water tank, a flocculation sedimentation device and a pre-concentrator connected in sequence, and the liquid outlet of the pre-concentrator is connected to the liquid inlet of the evaporation crystallization device.

[0015] According to the high-salt wastewater evaporation and crystallization treatment system provided by the present invention, a plug flow agitator is provided in the evaporation and crystallization device.

[0016] According to the high-salt wastewater evaporation and crystallization treatment system provided by the present invention, the evaporation and crystallization module further includes a salt mud storage device, and the salt mud storage device is connected to the slag discharge port of the evaporation and crystallization device.

[0017] Another aspect of the present invention provides a method for treating high-salt wastewater by evaporation and crystallization based on any of the above high-salt wastewater evaporation and crystallization treatment systems, comprising:

[0018] Passing the high-salt wastewater stock solution into the pretreatment module for pretreatment, removing suspended matter and COD in the high-salt wastewater stock solution and reducing the water content in the high-salt wastewater stock solution to obtain the first wastewater;

[0019] The first wastewater is introduced into the evaporation crystallization device, and the steam generator introduces steam into the heat exchanger to heat the first wastewater in the evaporation crystallization device. The circulating fan introduces the circulating air flowing out of the gas phase outlet of the steam-water separator into the evaporation crystallization device to directly contact the first wastewater for mass and heat transfer, so that the moisture in the first wastewater is evaporated under the action of the circulating air flowing out of the gas phase outlet of the steam-water separator.

[0020] Working principle:

[0021] The high-salt wastewater evaporation crystallization treatment system provided by the present invention pre-treats the high-salt wastewater stock solution in the wastewater treatment module to remove suspended matter and COD in the high-salt wastewater stock solution and reduce the water content in the high-salt wastewater stock solution. After the pretreatment is completed, the wastewater is passed into the evaporation crystallization device, and the steam generator passes steam into the heat exchanger to heat the first wastewater in the evaporation crystallization device. At the same time, the circulating fan introduces the gas flowing out of the gas phase outlet of the steam-water separator into the evaporation crystallization device for direct contact with the first wastewater for mass and heat transfer, so that the moisture in the first wastewater is evaporated under the action of the circulating air flowing out of the gas phase outlet of the steam-water separator. The high-temperature humid air after absorbing heat enters the steam heat pump unit through the air outlet of the evaporation crystallization device. The steam heat pump unit extracts and recovers the heat in the circulating air and transfers it to the circulating hot water in the hot water path of the steam heat pump unit. After the heat extraction, the temperature of the circulating air is reduced, and the water is condensed and precipitated, and enters the steam-water separator. Under the steam-water separation action of the steam-water separator, the circulating air enters the evaporation crystallization device again to continue to carry the water evaporated by the heat in the evaporation crystallization device, thereby concentrating and crystallizing the wastewater.

[0022] The high-salt wastewater evaporation and crystallization treatment system and method provided by the present invention solve the defects of low thermal energy utilization and slow evaporation and crystallization efficiency in the high-salt wastewater treatment methods in the prior art, and improve the heat utilization efficiency and separation efficiency in the concentration and crystallization process of high-salt wastewater.

[0023] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is one of the schematic diagrams of the high-salt wastewater evaporation and crystallization treatment system provided by an embodiment of the present invention;

[0026] Figure 2 This is the second schematic diagram of the high-salt wastewater evaporation and crystallization treatment system provided by an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of the process of evaporation and crystallization treatment of high-salt wastewater provided by an embodiment of the present invention.

[0028] Reference numerals:

[0029] 1. Pretreatment module; 101. Raw water tank; 102. Flocculation sedimentation tank; 103. Pre-concentrator; 104. Raw water pump;

[0030] 2. Evaporation crystallization module; 201. Evaporation crystallization device; 202. Heat exchanger; 203. Plug flow agitator; 204. Salt mud storage; 205. Defoamer;

[0031] 3. Steam heat pump module; 301. Steam heat pump unit; 302. Steam generator; 303. Pressure water tank; 304. Drive pump; 305. Circulation pump;

[0032] 4. Air circulation module; 401. Steam-water separator; 402. Circulation fan;

[0033] 5. External drainage module; 501. Crystallization water production tank; 502. External drainage processor. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0035] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0036] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0037] The following combination Figures 1 to 3 The present invention provides a system and method for evaporating and crystallizing high-salt wastewater.

[0038] like Figure 1 and Figure 2 As shown, on one hand, the present invention provides a high-salt wastewater evaporation crystallization treatment system, comprising: a pretreatment module 1, an evaporation crystallization module 2, a steam heat pump module 3 and an air circulation module 4, the evaporation crystallization module 2 includes an evaporation crystallization device 201 and a heat exchanger 202, the steam heat pump module 3 includes a steam heat pump unit 301 and a steam generator 302, and the air circulation module 4 includes a steam-water separator 401;

[0039] The heat exchanger 202 is connected to the evaporation crystallization device 201. The heat exchanger 202 is used to perform heat exchange with the high-salt wastewater in the evaporation crystallization device 201. The liquid inlet of the evaporation crystallization device 201 is connected to the pretreatment module 1.

[0040] The gas source side inlet of the steam heat pump unit 301 is connected to the gas outlet of the evaporation crystallization device 201, the gas source side outlet of the steam heat pump unit 301 is connected to the inlet of the steam-water separator 401, the gas phase outlet of the steam-water separator 401 is connected to the gas inlet of the evaporation crystallization device 201, the liquid outlet of the steam heat pump unit 301 is connected to the liquid inlet of the steam generator 302, the steam outlet of the steam generator 302 is connected to the steam inlet of the heat exchanger 202, and the liquid outlet of the steam generator 302 is connected to the liquid inlet of the steam heat pump unit 301.

[0041] Specifically, if Figure 2 As shown, in this embodiment, the pretreatment module 1 includes a raw water tank 101, a flocculation sedimentation vessel 102, and a pre-concentrator 103, which are connected in sequence. The liquid outlet of the pre-concentrator 103 is connected to the liquid inlet of the evaporation crystallization device 201. The raw water tank 101 is used to store high-salinity wastewater stock solution, the flocculation sedimentation vessel 102 is used to remove suspended matter and COD from the high-salinity wastewater stock solution, and reduce the degree of adhesion of materials in the subsequent evaporation crystallization device 201. The pre-concentrator 103 can concentrate the wastewater, reduce the water content in the high-salinity wastewater stock solution, reduce the moisture content of the materials entering the subsequent evaporation crystallization device 201, and improve wastewater treatment efficiency. In specific implementation, the appropriate pre-concentration equipment can be selected based on the concentration and type of salt substances in the high-salinity wastewater.

[0042] like Figure 2 As shown, in this embodiment, the liquid inlet of the evaporation crystallization device 201 is arranged on one side of the device, the gas outlet and the slag outlet of the evaporation crystallization device 201 are arranged on the side opposite to the liquid inlet, and the evaporation crystallization device 201 is provided with a plug flow agitator 203 for transferring wastewater from one end of the device ( Figure 2 The right end shown) pushes the flow to the other end ( Figure 2 left end as shown) and mix the wastewater evenly.

[0043] like Figure 2 As shown, in this embodiment, the evaporation crystallization module 2 further includes a salt mud storage 204, which is connected to the slag discharge port of the evaporation crystallization device 201 for storing salt mud and transporting it for disposal as required.

[0044] like Figure 2 As shown, in this embodiment, a demister 205 is provided within the evaporation crystallization apparatus 201. As the water in the high-salinity wastewater evaporates after mass and heat transfer and is carried out by the circulating air, the high-salinity wastewater may produce non-condensable gases that carry liquid, generating a large number of bubbles and subsequently forming foam. To prevent the foam containing pollutants from being discharged into the outside world with the air, the demister 205 provided at the top of the evaporation crystallization apparatus 201 can trap the foam within the evaporation crystallization apparatus 201 to prevent air pollution.

[0045] In this embodiment, the heat exchanger 202 is a heat exchange jacket connected to the evaporation crystallization device 201. When high-temperature steam is introduced into the heat exchange jacket, the high-salt wastewater in the evaporation crystallization device 201 can be indirectly heated. The steam generator 302 is a flash evaporator.

[0046] The high-salt wastewater evaporation and crystallization treatment system provided by the present invention solves the defects of low thermal energy utilization and slow evaporation and crystallization efficiency in the high-salt wastewater treatment method in the prior art, and improves the heat utilization efficiency and separation efficiency in the concentration and crystallization process of high-salt wastewater.

[0047] like Figure 2 As shown, in this embodiment of the present invention, the condensed water outlet of the heat exchanger 202 is connected to the liquid inlet of the steam heat pump unit 301. By connecting the condensed water outlet of the heat exchanger 202 to the liquid inlet of the steam heat pump unit 301, the condensed water generated in the heat exchanger 202 can be recirculated into the steam heat pump unit 301 for reuse.

[0048] like Figure 2 As shown, in this embodiment of the present invention, the steam heat pump module 3 further includes a pressurized water tank 303. A first liquid inlet of the pressurized water tank 303 is connected to the liquid outlet of the steam generator 302, a second liquid inlet of the pressurized water tank 303 is connected to the condensed water outlet of the heat exchanger 202, and a liquid outlet of the pressurized water tank 303 is connected to the liquid inlet of the steam heat pump unit 301. By providing the pressurized water tank 303, the unevaporated liquid in the steam generator 302 can be introduced into it for buffering and, when needed, pumped into the steam heat pump unit 301 for reuse via the circulating pump 305.

[0049] like Figure 2 As shown, in a further embodiment of the present invention, a driving pump 304 is provided on the pipeline connecting the first liquid inlet of the pressure water tank 303 and the liquid outlet of the steam generator 302. Providing the driving pump 304 on the pipeline connecting the first liquid inlet of the pressure water tank 303 and the liquid outlet of the steam generator 302 facilitates pumping unevaporated liquid in the steam generator 302 into the pressure water tank for storage during wastewater treatment.

[0050] like Figure 2 As shown, in this embodiment of the present invention, the air circulation module 4 further includes a circulation fan 402, which is disposed in a pipeline connecting the gas phase outlet of the steam-water separator 401 and the air inlet of the evaporation crystallization device 201. The installation of the circulation fan 402 in the pipeline connecting the gas phase outlet of the steam-water separator 401 and the air inlet of the evaporation crystallization device 201 facilitates the flow of circulating air into the evaporation crystallization device 201 during wastewater treatment to facilitate mass and heat transfer with the wastewater.

[0051] like Figure 2 As shown, in the embodiment of the present invention, the high-salt wastewater evaporation and crystallization treatment system further includes an external drainage module 5, which facilitates subsequent treatment of the wastewater treated by the evaporation and crystallization device 201 to meet the discharge requirements.

[0052] Specifically, in this embodiment, the external drainage module 5 includes a crystallization water tank 501 and an external drainage processor 502, which are connected in sequence. The liquid phase outlet of the steam-water separator 401 is connected to the liquid inlet of the crystallization water tank 501. The crystallization water tank 501 is used to temporarily store the desalinated water. After a certain amount of water accumulates, it is passed to the drainage processor for pre-discharge treatment. The wastewater is deaminated and disinfected to meet wastewater discharge standards.

[0053] like Figures 1 to 3 As shown, another aspect of the present invention provides a high-salt wastewater evaporation and crystallization treatment method based on the high-salt wastewater evaporation and crystallization treatment system described in any of the above embodiments, comprising:

[0054] The high-salt wastewater stock solution is passed into the pretreatment module 1 for pretreatment to remove suspended matter and COD in the high-salt wastewater stock solution and reduce the water content in the high-salt wastewater stock solution to obtain the first wastewater;

[0055] The first wastewater is introduced into the evaporation crystallization device 201, and the steam generator 302 introduces steam into the heat exchanger 202 to heat the first wastewater in the evaporation crystallization device 201. The circulating fan 402 introduces the gas flowing out of the gas phase outlet of the steam-water separator 401 into the evaporation crystallization device 201 to contact with the first wastewater for mass and heat transfer, so that the water in the first wastewater is evaporated under the action of the gas flowing out of the gas phase outlet of the steam-water separator 401.

[0056] The following combination Figures 1 to 3 The high-salt wastewater evaporation and crystallization treatment method provided by the present invention is specifically described.

[0057] The high-salinity wastewater is pumped from the raw water tank 101 by the raw water pump 104 and then fed into the flocculation and sedimentation unit 102. This removes suspended solids and COD from the high-salinity wastewater, reducing the degree of adhesion of the materials in the subsequent evaporation and crystallization unit 201. After flocculation and sedimentation, the high-salinity wastewater enters the pre-concentrator 103 for pre-concentration, reducing the water content of the high-salinity wastewater, reducing the moisture content of the materials entering the subsequent evaporation and crystallization unit 201, and improving wastewater treatment efficiency. The conductivity of the high-salinity wastewater obtained after pre-concentration is 250 ms / cm to 400 ms / cm, preferably 350 ms / cm in this embodiment.

[0058] The high-salt wastewater after pretreatment is introduced into the evaporation crystallization device 201. The high-salt wastewater is evenly mixed under the action of the plug flow agitator 203 and gradually moves from one end of the evaporation crystallization device 201 to the other end. Finally, it enters the salt mud storage tank from the slag discharge port of the evaporation crystallization device 201 in the form of solid crystallized salt mud and is transported out for disposal as required.

[0059] During the evaporation and crystallization process of high-salt wastewater in the evaporation and crystallization device 201, circulating air enters the circulation fan 402 from the gas phase outlet of the steam-water separator 401. Driven by the circulation fan 402, the circulating air pressure is increased to a set value before entering the evaporation and crystallization device 201. As the circulating air flows from one end of the evaporation and crystallization device 201 to the other, it fully contacts the high-salt wastewater for mass and heat transfer. After mass and heat transfer, the water in the high-salt wastewater evaporates and enters the steam heat pump unit 301 under the action of the circulating air. During this process, since the high-salt wastewater may produce non-condensable gas carrying liquid, a large number of bubbles are generated and foam is formed. To prevent the foam containing pollutants from being discharged to the outside with the air, the demister 205 installed at the top of the evaporation and crystallization device 201 can intercept the foam within the evaporation and crystallization device 201 to prevent it from polluting the air.

[0060] After absorbing heat, the high-temperature, moist air is discharged from the outlet of the evaporation crystallization device 201, and the circulating air enters the steam heat pump unit 301 through the air inlet of the steam heat pump unit 301. The steam heat pump unit 301 extracts and recovers the heat from the circulating air and transfers it to the circulating hot water in the hot water path of the steam heat pump unit 301.

[0061] After heat extraction, the temperature of the circulating air decreases, and the water is condensed and precipitated before entering the steam-water separator 401. Under the steam-water separation action of the steam-water separator 401, the circulating air passes through the circulating fan 402 and enters the evaporation crystallization device 201 again. The condensed water enters the crystallization water production tank 501 from the liquid phase outlet of the steam-water separator 401, and then enters the external water treatment equipment and is discharged after meeting the standards.

[0062] The circulating hot water after absorbing heat from the steam heat pump unit 301 enters the steam generator 302, and the steam generated by the steam generator 302 is discharged from its steam outlet to the heat exchanger 202 for heat exchange with the high-salt wastewater in the evaporation crystallization device 201, so that the high-salt wastewater is continuously heated to the set temperature (60°C to 95°C, preferably 85°C in this embodiment). The unevaporated hot water is discharged from the liquid outlet of the steam generator 302 and enters the pressure water tank 303 under the lifting action of the driving pump 304. After mixing with the steam condensed water discharged from the heat exchanger 202, the pressurized hot water is discharged from the water outlet of the pressure water tank 303 and enters the hot water passage of the steam heat pump unit 301 under the lifting action of the circulating pump 305.

[0063] Repeat the above steps until all high-salt wastewater is treated.

[0064] From the description of the above embodiments, it can be seen that the high-salt wastewater evaporation and crystallization treatment system provided by the present invention has at least the following advantages:

[0065] (1) The high-salt wastewater evaporation and crystallization treatment system provided by the present invention solves the defects of low thermal energy utilization and slow evaporation and crystallization efficiency in the high-salt wastewater treatment method of the prior art, and improves the heat utilization efficiency and separation efficiency in the concentration and crystallization process of high-salt wastewater.

[0066] (2) The high-salt wastewater evaporation and crystallization treatment system provided by the present invention can achieve full quantitative treatment of high-salt wastewater and achieve zero discharge of wastewater;

[0067] (3) The high-salt wastewater evaporation and crystallization treatment system provided by the present invention uses circulating air as a carrier to extract water from high-salt wastewater. The continuous and stable operation of the treatment process effectively improves the efficiency of evaporation and crystallization;

[0068] (4) The high-salt wastewater evaporation and crystallization treatment system provided by the present invention can fully extract and recycle the heat of the system when there is only electricity and no other heat source, thus saving energy;

[0069] (5) The high-salt wastewater evaporation and crystallization treatment system provided by the present invention can operate at normal pressure. Compared with vacuum devices, the equipment sealing requirements are low and the operation and maintenance are convenient;

[0070] (6) The high-salt wastewater evaporation and crystallization treatment system provided by the present invention has a simple structure, is easy to operate, can be unmanned, occupies a small area, has high space utilization, does not require the addition of exogenous agents, and is applicable to the treatment of various types of high-salt wastewater.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A high-salt wastewater evaporation and crystallization treatment system, characterized in that: include: A pretreatment module, an evaporation crystallization module, a steam heat pump module and an air circulation module, wherein the evaporation crystallization module includes an evaporation crystallization device and a heat exchanger, the steam heat pump module includes a steam heat pump unit and a steam generator, and the air circulation module includes a steam-water separator; The heat exchanger is connected to the evaporation crystallization device, and the heat exchanger is used to perform heat exchange with the high-salt wastewater in the evaporation crystallization device. The liquid inlet of the evaporation crystallization device is connected to the pretreatment module; The gas source side inlet of the steam heat pump unit is connected to the gas outlet of the evaporation crystallization device, the gas source side outlet of the steam heat pump unit is connected to the inlet of the steam-water separator, the gas phase outlet of the steam-water separator is connected to the gas inlet of the evaporation crystallization device, the liquid outlet of the steam heat pump unit is connected to the liquid inlet of the steam generator, the steam outlet of the steam generator is connected to the steam inlet of the heat exchanger, and the liquid outlet of the steam generator is connected to the liquid inlet of the steam heat pump unit; The steam heat pump module further includes a pressurized water tank, wherein a first liquid inlet of the pressurized water tank is connected to a liquid outlet of the steam generator, a second liquid inlet of the pressurized water tank is connected to a condensed water outlet of the heat exchanger, and a liquid outlet of the pressurized water tank is connected to a liquid inlet of the steam heat pump unit; The air circulation module further includes a circulation fan, which is arranged on a pipeline connecting the gas phase outlet of the steam-water separator and the air inlet of the evaporation crystallization device; The pretreatment module comprises a raw water tank, a flocculation sedimentation device and a pre-concentrator connected in sequence, and the liquid outlet of the pre-concentrator is connected to the liquid inlet of the evaporation crystallization device; A plug flow stirrer is provided in the evaporation crystallization device.

2. The high-salt wastewater evaporation and crystallization treatment system according to claim 1, characterized in that: The condensed water outlet of the heat exchanger is connected to the liquid inlet of the steam heat pump unit.

3. The high-salt wastewater evaporation and crystallization treatment system according to claim 1, characterized in that: A driving pump is provided on the pipeline connecting the first liquid inlet of the pressure water tank and the liquid outlet of the steam generator.

4. The high-salt wastewater evaporation and crystallization treatment system according to claim 1, characterized in that: It also includes an external drainage module, which includes a crystallization water production tank and an external drainage processor connected in sequence, and the liquid phase outlet of the steam-water separator is connected to the liquid inlet of the crystallization water production tank.

5. The high-salt wastewater evaporation and crystallization treatment system according to claim 1, characterized in that: The evaporation crystallization module further includes a salt mud storage device, and the salt mud storage device is connected to the slag discharge port of the evaporation crystallization device.

6. A method for treating high-salt wastewater by evaporation and crystallization based on the high-salt wastewater evaporation and crystallization treatment system according to any one of claims 1 to 5, characterized in that: include: Passing the high-salt wastewater stock solution into the pretreatment module for pretreatment, removing suspended matter and COD in the high-salt wastewater stock solution and reducing the water content in the high-salt wastewater stock solution to obtain the first wastewater; The first wastewater is introduced into the evaporation crystallization device, and the steam generator introduces steam into the heat exchanger to heat the first wastewater in the evaporation crystallization device. The circulating fan introduces the circulating air flowing out of the gas phase outlet of the steam-water separator into the evaporation crystallization device to directly contact the first wastewater for mass and heat transfer, so that the moisture in the first wastewater is evaporated under the action of the circulating air flowing out of the gas phase outlet of the steam-water separator.

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