Energy-saving salt lake brine treatment device

Abstract

The application relates to an energy-saving salt lake brine treatment device, which comprises a heat exchanger, a falling film heater, a forced circulation heater, an evaporation crystallizer and a compressor. The salt lake brine to be treated is sequentially treated by the heat exchanger, the falling film heater, the forced circulation heater and the evaporation crystallizer. The compressor is used for carrying out preset temperature rise compression treatment on secondary steam generated by the falling film heater and the forced circulation heater. The compression steam outlet of the compressor is communicated with the heating steam inlet of the forced circulation heater through a first steam pipeline. The heating steam outlet of the forced circulation heater is communicated with the heating steam inlet of the falling film heater through an intermediate steam transmission pipeline. The compressed secondary steam is effectively used to sequentially heat the forced circulation heater and the falling film heater, segmented heating at different temperatures is realized, the front-stage heating is used for concentration, the rear-stage heating is used for crystallization, the heat utilization efficiency is improved, and the energy consumption of a lithium-sodium separation and concentration device is reduced.

Description

Technical Field

[0001] This application relates to the technical field of lithium extraction from salt lake brine, and more particularly to an energy-saving salt lake brine treatment device for lithium-sodium separation and concentration in the lithium extraction process from salt lake brine. Background Technology

[0002] Salt lake brine is rich in lithium chloride and sodium chloride, and is one of the main raw materials for lithium extraction. Related technologies in the lithium extraction process from salt lake brine introduce MVR (Mechanical Vapor Recompression) evaporation to separate and concentrate lithium and sodium from the raw brine to obtain a target mother liquor containing lithium and being a saturated sodium solution.

[0003] However, the lithium-sodium separation and concentration devices used in the lithium extraction process from salt lake brine still suffer from high energy consumption and high operating costs. Utility Model Content

[0004] In view of the above-mentioned problems in the prior art, the purpose of this application is to provide an energy-saving salt lake brine treatment device to at least solve the problems of high energy consumption and high operating costs of lithium-sodium separation and concentration devices used in the lithium extraction process of salt lake brine in the related art.

[0005] To address the aforementioned technical problems, this application provides an energy-saving salt lake brine treatment device, which includes:

[0006] The system includes a heat exchanger, a falling film heater, a forced circulation heater, an evaporator crystallizer, and a compressor. The brine from the salt lake to be treated is sequentially processed through the heat exchanger, the falling film heater, the forced circulation heater, and the evaporator crystallizer.

[0007] The compressor is used to compress the secondary steam generated by the falling film heater and the forced circulation heater to a preset temperature rise. The compressed steam outlet of the compressor is connected to the heating steam inlet of the forced circulation heater through a first steam pipeline. The heating steam outlet of the forced circulation heater is connected to the heating steam inlet of the falling film heater through an intermediate steam transmission pipeline.

[0008] In some exemplary embodiments, the preset temperature rise is 14°C, the heating temperature of the forced circulation heater is 95°C, and the heating temperature of the falling film heater is 90°C.

[0009] In some exemplary embodiments, the heat exchanger includes a first heat exchanger, a second heat exchanger, a third heat exchanger, and a fourth heat exchanger. The inlets of the first and second heat exchangers are respectively connected to the brine feed pipe of the salt lake. The outlets of the first and second heat exchangers are connected to the inlet of the third heat exchanger. The outlet of the third heat exchanger is connected to the inlet of the fourth heat exchanger. The outlet of the fourth heat exchanger is connected to the inlet of the falling film heater.

[0010] The heating temperatures of the first heat exchanger, the second heat exchanger, the third heat exchanger, and the fourth heat exchanger increase progressively.

[0011] In some exemplary embodiments, the heating temperature of the first heat exchanger is 50-55°C, the heating temperature of the second heat exchanger is 60-65°C, the heating temperature of the third heat exchanger is 70-75°C, and the heating temperature of the fourth heat exchanger is 85-90°C.

[0012] In some exemplary embodiments, the apparatus further includes a mother liquor tank, a condensate tank, and a fresh steam pipeline; the mother liquor tank is used to collect the treated mother liquor; the liquid inlet of the condensate tank is connected to the condensate outlet of the falling film heater and the forced circulation heater, respectively.

[0013] The heating medium inlet of the fourth heat exchanger is connected to the fresh steam pipeline, and the liquid inlet of the condensate tank is also connected to the condensate outlet of the fourth heat exchanger.

[0014] The heating medium inlet of the third heat exchanger is connected to the secondary non-condensable gas outlets of the falling film heater and the forced circulation heater, respectively, and the liquid inlet of the condensate tank is also connected to the condensate outlet of the third heat exchanger.

[0015] The heating medium inlet of the second heat exchanger is connected to the mother liquor tank, and the mother liquor after heat exchange is discharged from the second heat exchanger and connected to the mother liquor outlet pipe;

[0016] The heating medium inlet of the first heat exchanger is connected to the distilled water outlet of the condensate tank, and the distilled water after heat exchange is discharged from the first heat exchanger and connected to the distilled water outlet pipe.

[0017] In some exemplary embodiments, the water vapor outlet of the condensate tank is connected to the falling film heater via a water vapor pipeline, so that the water vapor generated by the condensate tank enters the falling film heater.

[0018] In some exemplary embodiments, the first steam pipeline is connected to the fresh steam pipeline via a first connecting pipeline, the first connecting pipeline being provided with a regulating valve.

[0019] In some exemplary embodiments, the first and second heat exchangers are plate-fin heat exchangers, and the third and fourth heat exchangers are tube-fin heat exchangers or shell-and-tube heat exchangers.

[0020] In some exemplary embodiments, the device further includes a liquid collection tank, the liquid inlet of which is connected to the liquid discharge outlet of the compressor, and the liquid outlet of which is connected to the liquid inlet of the condensate tank.

[0021] In some exemplary embodiments, the apparatus further includes a gas-liquid separator and a gas scrubbing tower. The gas-liquid separator is used to separate the secondary steam generated by the falling film heater into gas and liquid components. The outlet of the gas-liquid separator is connected to the inlet of the gas scrubbing tower. The outlet of the evaporator crystallizer is connected to the inlet of the gas scrubbing tower. The outlet of the gas scrubbing tower is connected to the inlet of the compressor.

[0022] The energy-saving brine treatment device of this application includes a heat exchanger, a falling film heater, a forced circulation heater, an evaporator crystallizer, and a compressor. The brine to be treated passes through the heat exchanger, falling film heater, forced circulation heater, and evaporator crystallizer sequentially. The compressor is used to compress the secondary steam generated by the falling film heater and the forced circulation heater to a preset temperature rise. The compressed steam outlet of the compressor is connected to the heating steam inlet of the forced circulation heater through a first steam pipeline. The heating steam outlet of the forced circulation heater is connected to the heating steam inlet of the falling film heater through an intermediate steam transmission pipeline. This effectively utilizes the compressed steam to heat the forced circulation heater and the falling film heater sequentially, achieving segmented heating at different temperatures. The first stage of heating is used for concentration, and the second stage of heating is used for crystallization, improving heat utilization efficiency and thus reducing the energy consumption and operating costs of the lithium-sodium separation and concentration device in the lithium extraction process from brine. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of an energy-saving salt lake brine treatment device provided in an embodiment of this application;

[0025] In the picture:

[0026] 1-Heat exchanger, 2-Falling film heater, 3-Forced circulation heater, 4-Evaporator crystallizer, 5-Compressor, 6-Mother liquor tank, 7-Condensate tank, 8-Accumulated liquid tank, 9-Gas scrubbing tower, 10-Gas-liquid separator, 100-Centrifuge;

[0027] 11-First heat exchanger, 12-Second heat exchanger, 13-Third heat exchanger, 14-Fourth heat exchanger; 21, 31-Heating steam inlet, 32-Heating steam outlet, 23, 33-Secondary non-condensable gas outlet, 24, 34-Condensate outlet, 51-Compressed steam outlet, 52-Liquid outlet, 71-Liquid inlet, 72-Distilled water outlet;

[0028] 01-First steam pipeline, 02-Intermediate steam transmission pipeline, 03-Brine feed pipeline, 04-Fresh steam pipeline, 05-Mother liquor discharge pipeline, 06-Distilled water discharge pipeline, 07-Steam pipeline, 08-First connecting pipeline; 001-Regulating valve. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0031] This application provides an energy-saving salt lake brine treatment device, such as... Figure 1 As shown, the brine to be treated is transported to the energy-saving brine treatment device of this application embodiment through the brine feed pipeline 03 for lithium and sodium separation and concentration treatment to obtain the target mother liquor, which contains lithium and is a saturated sodium solution. The treated target mother liquor is discharged through the mother liquor discharge pipeline 05.

[0032] Specifically, the temperature of the brine to be treated is approximately 25°C. This brine is rich in sodium chloride and lithium chloride, with lithium ions (L...) + The concentration is approximately 0.3–2.5 g / L, and the sodium ion Na... + The concentration is approximately 70–85 g / L, and the lithium ion concentration in the target mother liquor after treatment is L + The concentration is approximately 6–6.5 g / L, with sodium ions (Na) + The concentration is approximately 110–120 g / L (i.e., a saturated sodium solution).

[0033] See also Figure 1 The energy-saving salt lake brine treatment device of this application embodiment includes a heat exchanger 1, a falling film heater 2, a forced circulation heater 3, an evaporator crystallizer 4 and a compressor 5. The salt lake brine to be treated is transported to the energy-saving salt lake brine treatment device 100 through the salt lake brine feed pipeline 03, and then passes through the heat exchanger 1, the falling film heater 2, the forced circulation heater 3 and the evaporator crystallizer 4 in sequence for treatment.

[0034] The heat exchanger 1 is used to preheat the temperature of the salt lake brine to be treated to 90°C. The preheated salt lake brine can be pumped from top to bottom into the falling film heater 2 by a pump (such as a circulating pump). The falling film heater 2 is used to concentrate the brine. The concentrated brine flowing out of the falling film heater 2 can be pumped from bottom to top into the forced circulation heater 3 by a pump (such as a circulating pump). The concentrated liquid flowing out of the forced circulation heater 3 enters the evaporator crystallizer 4 for evaporation and crystallization, thereby achieving the separation of sodium chloride crystals and lithium chloride solution to obtain the target mother liquor.

[0035] The compressor 5 is used to compress the secondary steam generated by the falling film heater 2 and the secondary steam generated by the forced circulation heater 3 to a preset temperature rise. The compressed steam outlet 51 of the compressor 5 is connected to the heating steam inlet 31 of the forced circulation heater 3 through the first steam pipeline 01. The heating steam outlet 32 ​​of the forced circulation heater 3 is connected to the heating steam inlet 21 of the falling film heater 2 through the intermediate steam transmission pipeline 02. Thus, the compressed steam discharged from the compressed steam outlet 51 of the compressor 5 is used as the heating medium of the forced circulation heater 3 and the falling film heater 2 in sequence, realizing segmented heating at different temperatures. This makes the heating temperature of the falling film heater 2 in the first stage lower than the heating temperature of the forced circulation heater 3 in the second stage. The first stage heating is used for concentration, and the second stage heating is used for crystallization. This segmented heating method not only improves the heat utilization efficiency and reduces the energy consumption and operating cost of the lithium-sodium separation and concentration device in the lithium extraction process of salt lake brine, but also avoids the phenomenon of sodium chloride crystallization in the falling film heater 2, thus improving the stability of the device operation.

[0036] In some exemplary embodiments, the preset temperature rise of the compressor 5 is 14°C, the heating temperature of the forced circulation heater 3 is 95°C, and the heating temperature of the falling film heater 2 is 90°C, thereby achieving higher thermal efficiency.

[0037] In some exemplary implementations, such as Figure 1 As shown, heat exchanger 1 may include a first heat exchanger 11, a second heat exchanger 12, a third heat exchanger 13 and a fourth heat exchanger 14, and the heating temperature of the first heat exchanger 11, the second heat exchanger 12, the third heat exchanger 13 and the fourth heat exchanger 14 increases step by step. The inlets of the first heat exchanger 11 and the second heat exchanger 12 are connected to the brine feed pipeline 03, allowing the brine to be treated in the brine feed pipeline 03 to enter the first heat exchanger 11 and the second heat exchanger 12 for synchronous heating. The outlets of the first heat exchanger 11 and the second heat exchanger 12 are both connected to the inlet of the third heat exchanger 13, allowing the brine heated by the first heat exchanger 11 and the second heat exchanger 12 to enter the third heat exchanger 13 for heating. The outlet of the third heat exchanger 13 is connected to the inlet of the fourth heat exchanger 14, allowing the brine heated by the third heat exchanger 13 to enter the fourth heat exchanger 14 for heating. The outlet of the fourth heat exchanger 14 is connected to the inlet 21 of the falling film heater 2, allowing the brine heated by the fourth heat exchanger 14 to enter the falling film heater 2. By using multiple heat exchangers to gradually increase the temperature of the salt lake brine, more precise control of the temperature during the preheating stage can be achieved.

[0038] In some exemplary embodiments, the heating temperature of the first heat exchanger 11 is 50-55°C, the heating temperature of the second heat exchanger 12 is 60-65°C, the heating temperature of the third heat exchanger 13 is 70-75°C, and the heating temperature of the fourth heat exchanger 14 is 85-90°C, thereby achieving better heating efficiency.

[0039] In some exemplary implementations, see further. Figure 1 To further reduce energy consumption and achieve higher thermal efficiency, the energy-saving salt lake brine treatment device of this application embodiment may further include a mother liquor tank 6, a condensate tank 7, and a fresh steam pipeline 04. The mother liquor tank 6 is used to collect the treated mother liquor, i.e., the target mother liquor. The liquid inlet 71 of the condensate tank 7 is connected to the condensate outlet 24 of the falling film heater 2 and the condensate outlet 34 of the forced circulation heater 3, respectively, to collect the condensate generated by the falling film heater 2 and the condensate generated by the forced circulation heater 3, so as to realize the recovery and utilization of the heat of the condensate. The fresh steam pipeline 04 is used to transport fresh steam.

[0040] The heating medium inlet of the fourth heat exchanger 14 is connected to the fresh steam pipeline 04, and the liquid inlet 71 of the condensate tank 6 is also connected to the condensate outlet of the fourth heat exchanger 14. Thus, the fourth heat exchanger 14 can use the fresh steam in the fresh steam pipeline 04 as a heat medium to heat the brine flowing through it to 85-90°C. At the same time, the condensate water after the heat medium is condensed can be collected by the condensate tank 7 to realize the recovery and utilization of the heat of the condensate water.

[0041] The heating medium inlet of the third heat exchanger 13 is connected to the secondary non-condensable gas outlet 23 of the falling film heater 2 and the secondary non-condensable gas outlet 33 of the forced circulation heater 3, respectively. The liquid inlet 71 of the condensate tank 7 is also connected to the condensate outlet of the third heat exchanger 13. Thus, the third heat exchanger 13 can use the secondary non-condensable gas generated by the falling film heater 2 and the secondary non-condensable gas generated by the forced circulation heater 3 as heat medium to heat the brine flowing through it to 70-75°C. At the same time, the condensate water after the heat medium is condensed can be collected by the condensate tank 7 to realize the recovery and utilization of the heat of the condensate water.

[0042] The heating medium inlet of the second heat exchanger 12 is connected to the mother liquor tank 6, so that the target mother liquor in the mother liquor tank 6 is used as the heat medium of the second heat exchanger 12 to heat the brine flowing through it to 60-65°C. After the heat exchange, the mother liquor is discharged from the second heat exchanger 12 and connected to the mother liquor discharge pipeline 05, and discharged through the mother liquor discharge pipeline 05, thus realizing the recovery and utilization of the heat of the target mother liquor.

[0043] The heating medium inlet of the first heat exchanger 11 is connected to the distilled water outlet 72 of the condensate tank 7, so that the distilled water generated by the condensate tank 7 is used as the heat medium of the first heat exchanger 11 to heat the brine flowing through it to 50-55°C. After heat exchange, the distilled water is discharged from the first heat exchanger 11 and connected to the distilled water outlet pipe 06, and discharged through the distilled water outlet pipe 06, thus realizing the recovery and utilization of the heat of the distilled water generated by the condensate tank 7.

[0044] The above-described implementation method fully utilizes the heat from the condensate, mother liquor, and secondary non-condensable gas to achieve a step-by-step temperature increase of the brine in multiple heat exchangers, which greatly improves the thermal efficiency of the entire device and reduces energy consumption.

[0045] In specific implementation, considering that the heating temperature of the first heat exchanger 11 and the second heat exchanger 12 is relatively low, and the pressure of the heat medium used is also relatively low, the first heat exchanger 11 and the second heat exchanger 12 can be plate-fin heat exchangers; while the heating temperature of the third heat exchanger 13 and the fourth heat exchanger 14 is relatively high, and the pressure of the heat medium used is also relatively high, so the third heat exchanger 13 and the fourth heat exchanger 14 can be tube-fin heat exchangers or shell-and-tube heat exchangers. In this way, while making full use of heat mediums of different temperature and pressure levels to preheat the brine of the salt lake, the stability of the device operation can be improved.

[0046] In some exemplary implementations, see further. Figure 1 The steam outlet of the condensate tank 7 is connected to the falling film heater 2 through the steam pipeline 07, so that the steam generated by the condensate tank 7 enters the shell side of the falling film heater 2, thereby realizing further recovery and utilization of the heat of the condensate and improving the thermal efficiency of the entire device.

[0047] In some exemplary implementations, see further. Figure 1 The first steam pipeline 01 is connected to the fresh steam pipeline 04 through the first connecting pipeline 08, and the first connecting pipeline 08 is equipped with a regulating valve 001. The ratio of compressed steam to fresh steam in the heating medium delivered to the forced circulation heater 3 through the first steam pipeline 01 can be adjusted by the regulating valve 001, thereby achieving more stable heating temperature control and improving the stability of the device.

[0048] In some exemplary implementations, see further. Figure 1 The energy-saving salt lake brine treatment device in this application embodiment may further include a liquid collection tank 8. The liquid inlet of the liquid collection tank 8 is connected to the liquid discharge outlet 52 of the compressor 5 for collecting the liquid water after compression by the compressor 5. The liquid outlet of the liquid collection tank 8 is connected to the liquid inlet 71 of the condensate tank 7. Thus, the heat of the liquid water can be recovered and utilized through the heating / heat exchange devices connected to the condensate tank 7, which further improves the thermal efficiency of the device in this application embodiment and reduces energy consumption.

[0049] In some exemplary implementations, see further. Figure 1The energy-saving salt lake brine treatment device of this application embodiment may further include a gas-liquid separator 10 and a gas scrubbing tower 9. The gas-liquid separator 10 is used to separate the secondary steam generated by the falling film heater 2. The outlet of the gas-liquid separator 10 is connected to the inlet of the gas scrubbing tower 9, so that the secondary steam separated by the gas-liquid separator 10 enters the gas scrubbing tower 9 for gas scrubbing. At the same time, the outlet of the evaporator crystallizer 4 is also connected to the inlet of the gas scrubbing tower 9, so that the secondary steam separated by the evaporator crystallizer 4 enters the gas scrubbing tower 9 for gas scrubbing. The secondary steam after being scrubbing by the gas scrubbing tower 9 enters the compressor 5. Under the action of the compressor 5, the preset temperature rise is increased, and the compressed steam outlet 51 of the compressor 5 enters the shell side of the forced circulation heater 3 through the first steam pipeline 01 as a heat medium for heating. Then, it enters the shell side of the falling film heater 2 again through the intermediate steam transmission pipeline 02 between the forced circulation heater 3 and the falling film heater 2 as a heat medium for heating. Thus, while improving the heat utilization efficiency, the stability of the device operation is ensured. Among them, the gas scrubbing tower 9 can scrub the secondary steam fed into the tower by spraying clean water, thereby reusing the secondary steam and avoiding damage to the compressor 5.

[0050] In practical applications, such as Figure 1 As shown, the energy-saving salt lake brine treatment device may also include a centrifuge 100. The crystallizing liquid in the evaporator crystallizer 4 first enters the centrifuge 100 for centrifugation treatment to separate sodium chloride crystals and lithium chloride solution to obtain the target mother liquor which enters the mother liquor tank 6.

[0051] The foregoing description has fully disclosed the specific embodiments of this application. It should be noted that any modifications made to the specific embodiments of this application by those skilled in the art do not depart from the scope of the claims. Accordingly, the scope of the claims is not limited to the foregoing specific embodiments.

Claims

1. An energy-saving brine treatment device for salt lakes, characterized in that, include: Heat exchanger (1), falling film heater (2), forced circulation heater (3), evaporator crystallizer (4) and compressor (5); the salt lake brine to be treated is processed sequentially through the heat exchanger (1), falling film heater (2), forced circulation heater (3) and evaporator crystallizer (4); The compressor (5) is used to compress the secondary steam generated by the falling film heater (2) and the forced circulation heater (3) to a preset temperature rise. The compressed steam outlet of the compressor (5) is connected to the heating steam inlet of the forced circulation heater (3) through the first steam pipeline (01). The heating steam outlet (32) of the forced circulation heater (3) is connected to the heating steam inlet of the falling film heater (2) through the intermediate steam transmission pipeline (02).

2. The energy-saving salt lake brine treatment device according to claim 1, characterized in that, The preset temperature rise is 14°C, the heating temperature of the forced circulation heater (3) is 95°C, and the heating temperature of the falling film heater (2) is 90°C.

3. The energy-saving salt lake brine treatment device according to claim 1, characterized in that, The heat exchanger (1) includes a first heat exchanger (11), a second heat exchanger (12), a third heat exchanger (13) and a fourth heat exchanger (14). The inlets of the first heat exchanger (11) and the second heat exchanger (12) are connected to the brine feed pipeline (03) of the salt lake, respectively. The outlets of the first heat exchanger (11) and the second heat exchanger (12) are connected to the inlet of the third heat exchanger (13). The outlet of the third heat exchanger (13) is connected to the inlet of the fourth heat exchanger (14). The outlet of the fourth heat exchanger (14) is connected to the inlet of the falling film heater (2). The heating temperatures of the first heat exchanger (11), the second heat exchanger (12), the third heat exchanger (13), and the fourth heat exchanger (14) increase progressively.

4. The energy-saving salt lake brine treatment device according to claim 3, characterized in that, The heating temperature of the first heat exchanger (11) is 50~55℃, the heating temperature of the second heat exchanger (12) is 60~65℃, the heating temperature of the third heat exchanger (13) is 70~75℃, and the heating temperature of the fourth heat exchanger (14) is 85~90℃.

5. The energy-saving salt lake brine treatment device according to claim 3, characterized in that, The device also includes a mother liquor tank (6), a condensate tank (7), and a fresh steam pipeline (04); the mother liquor tank (6) is used to collect the treated mother liquor; the liquid inlet of the condensate tank (7) is connected to the condensate outlet of the falling film heater (2) and the forced circulation heater (3), respectively. The heating medium inlet of the fourth heat exchanger (14) is connected to the fresh steam pipeline (04), and the liquid inlet of the condensate tank (7) is also connected to the condensate outlet of the fourth heat exchanger (14). The heating medium inlet of the third heat exchanger (13) is connected to the secondary non-condensable gas outlets of the falling film heater (2) and the forced circulation heater (3), respectively, and the liquid inlet of the condensate tank (7) is also connected to the condensate outlet of the third heat exchanger (13). The heating medium inlet of the second heat exchanger (12) is connected to the mother liquor tank (6), and the mother liquor after heat exchange is discharged from the second heat exchanger (12) and connected to the mother liquor discharge pipeline (05); The heating medium inlet of the first heat exchanger (11) is connected to the distilled water outlet of the condensate tank (7), and the distilled water after heat exchange is discharged from the first heat exchanger (11) and connected to the distilled water outlet pipe (06).

6. The energy-saving salt lake brine treatment device according to claim 5, characterized in that, The steam outlet of the condensate tank (7) is connected to the falling film heater (2) through a steam pipeline (07) so that the steam generated by the condensate tank (7) enters the falling film heater (2).

7. The energy-saving salt lake brine treatment device according to claim 5, characterized in that, The first steam pipeline (01) is connected to the fresh steam pipeline (04) through the first connecting pipeline (08), and the first connecting pipeline (08) is provided with a regulating valve (001).

8. The energy-saving salt lake brine treatment device according to any one of claims 3 to 7, characterized in that, The first heat exchanger (11) and the second heat exchanger (12) are plate-fin heat exchangers, and the third heat exchanger (13) and the fourth heat exchanger (14) are tube-fin heat exchangers or shell-and-tube heat exchangers.

9. The energy-saving salt lake brine treatment device according to claim 5, characterized in that, The device also includes a liquid collection tank (8), the liquid inlet of which is connected to the liquid discharge outlet of the compressor (5), and the liquid outlet of which is connected to the liquid inlet of the condensate tank (7).

10. The energy-saving salt lake brine treatment device according to claim 1, characterized in that, The device also includes a gas-liquid separator (10) and a gas scrubbing tower (9). The gas-liquid separator (10) is used to separate the secondary steam generated by the falling film heater (2) into gas and liquid. The outlet of the gas-liquid separator (10) is connected to the inlet of the gas scrubbing tower (9). The outlet of the evaporator crystallizer (4) is connected to the inlet of the gas scrubbing tower (9). The outlet of the gas scrubbing tower (9) is connected to the inlet of the compressor (5).

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